These crossovers are part of the Tommy Westphall Universe. Westphall does not include film crossovers, but I included them for completeness in some cases.
So far I connected Thomas Holbrook's groups 1, 2, 4, 6, 10, 12, 14, 15 (partial), 16, 18, 21, 24, 27, 29, 30, 32, 33, 34, 38, 39, and the DC Comics Multiverse.
Click the image for a better view. The series are placed closest to their strongest link.
Lucy Makes Room for Daddy
from CBS, ABC, NBC, and Showtime
After I Love Lucy was renamed to The Lucy-Desi Comedy Hour, Susie McNamera from Private Secretary appeared in the first episode Lucy Takes a Cruise to Havana.
Danny Williams from The Danny Thomas Show and the rest of the Williams family appeared in The Lucy-Desi Comedy HourLucy Makes Room for Danny. Lucy and Ricky Ricardo appeared in The Danny Thomas ShowLucy Upsets the Williams Household.
Lucy Richardo from The Lucy-Desi Comedy Hour appeared in The Ann Sothern ShowThe Lucy Story.
No crossover occurred when George Reeves from The Adventures of Superman appeared in I Love LucyLucy and Superman as himself. He stayed in character for the children in the audience. (people not considered)
Make Room for Daddy
Make Room for Daddy was renamed to The Danny Thomas Show, and it spun off Make Room For Granddaddy.
Danny Williams from Make Room for Daddy appeared in The Joey Bishop ShowThis Is Your Life.
José Jiménez appeared in eight episodes of Make Room for Daddy before spinning off to his own series The Bill Dana Show. (Holy defenestration, Batman!)
Andy Taylor appeared in Make Room for DaddyDanny Meets Andy Griffith which lead to the creation of The Andy Griffith Show. The Andy Griffith Show had three spin-offs: Gomer Pyle, U.S.M.C. (I'm not home!), Mayberry R.F.D., and The New Andy Griffith Show.
Barney Fife from The Andy Griffith Show appeared in on The Joey Bishop ShowJoey's Hideaway Cabin. Howard Sprague from The Andy Griffith Show appeared in It's Garry Shandling's ShowThe Day Howard Moved In.
Pvt. Gomer Pyle from Gomer Pyle, U.S.M.C. appeared in The Lucy ShowLucy Gets Caught Up in the Draft. (Lucy's Diagnosis)
Lucy Carter from Here's Lucy appeared in Make Room for Granddaddy "Lucy and the Lecher". (Lucy's Diagnosis)
Maurice Sorrell from The Dick Van Dyke Show appeared in The Danny Thomas ShowThe Woman Behind the Jokes. Alan Brady from The Dick Van Dyke Show appeared in Mad About YouThe Alan Brady Show. (Mad About Friends, Cheers!) Sally Rogers and Maurice Sorrell from The Dick Van Dyke Show appeared in Herman's HeadWhen Hairy Met Hermy. (I'm not home!)
A crossover between The Dick Van Dyke Show and Richard Diamond, Private Detective was attempted with Sam played by Mary Tyler Moore on Richard Diamond. Mary Tyler Moore played Laura Petrie on The Dick Van Dyke Show so there was NO cross.
from NBC, CBS, and ABC
Ralph Kramden from The Honeymooners appeared in Here's LucyLucy Visits Jack Benny. (I'm not home!) The Jackie Gleason Show turned The Honeymooners sketches into The Honeymooners which returned to The Jackie Gleason Show after being canceled.
Mary Jane Lewis from The Lucy Show appeared in Here's Lucy "A Date for Lucy" and recurs thereafter.
Joe Mannix from Mannix appeared in Here's LucyLucy and Mannix Are Held Hostage and on Diagnosis MurderHard-Boiled Murder.
Bob Collins from The Bob Cummings Show appeared in The George Burns and Gracie Allen ShowA Marital Mix-Up and Here's LucyLucy's Punctured Romance. The Bob Cummings Show spun off The New Bob Cummings Show and aired in syndication as Love That Bob.
Cinnamon Carter from Mission: Impossible appeared in Diagnosis MurderDiscards. Mission: Impossible spun off Mission: Impossible (1988).
Ben Matlock from Matlock appeared in the two-part Diagnosis MurderMurder Two. Promised LandTotal Security concludes on Diagnosis MurderPromises to Keep.
Diagnosis Murder is a spin off of Jake and the Fatman. Promised Land is a spin off of Touched By an Angel.
Diagnosis Murder used stock footage of Oceanic Airlines from the film Executive Decision not the logo from Lost. Crossovers with JAG (JAG and NCIS) and War at Home have been severed because they used the same stock footage.
Mad About Friends, Cheers!
from NBC and ABC
Cosmo Kramer from Seinfeld appeared in Mad About YouThe Apartment.
On Mad About YouPandora's Box, Jamie Buchman causes a blackout which was shared on Madman of the PeopleBirthday in the Big House and FriendsThe One with the Blackout.
Jamie Buchman, Fran Devanow, and Urusla Buffay from Mad About You appeared in FriendsThe One with Two Parts: Part 1. Mad About You and Friends characters Ursula and Phoebe Buffay are twin sisters.
Phoebe Buffay from Friends appeared in Hope and GloriaA New York Story when Hope and Gloria stopped by the Central Perk coffee shop.
Ross Geller from Friends appeared in The Single GuyNeighbors. On the same night, Chandler Bing from Friends and Jonathan Eliot from The Single Guy appeared in Caroline in the CityCaroline and the Folks.
Friends spun off Joey.
Daphne Moon and Niles Crane from Frasier appeared in Caroline in the CityCaroline and the Bad Back. Daphne reads Caroline in the City comic strip.
Cheers spun off The Tortellis and Frasier.
Norm Peterson and Cliff Clavin from Cheers appeared in WingsThe Story of Joe. Frasier and Lilith Sternin-Crane, also from Cheers, appeared in WingsPlanes, Trains and Visiting Cranes.
John Hemingway from The John Larroquette ShowMore Changes called Dr. Frasier Crane's radio show on Frasier. The John Larroquette Show's Yoydyne connection with Star Trek and Angel has been severed, though both appear later with other crossovers. (Weyland-Yutani)
Melville's restaurant above Cheers was mentioned on Boston LegalDesperately Seeking Shirley, a spin off of The Practice. (The Practice)
from ABC, NBC, and FOX
Several characters of The Practice appeared in Ally McBealThe Inmates, which ended on The PracticeAxe Murderer. Bobby Donnell from The Practice also appeared in Ally McBealThese Are the Days. Ally McBeal was renamed Ally.
Kevin Riley from Boston Public appeared in The PracticeThe Day After. Ellenor Frutt and Jimmy Berluti from The Practice appeared in Boston PublicChapter Thirteen.
Doctor Ben Gideon from Gideon's Crossing appeared in The PracticeGideon's Crossover. Ellenor Frutt from The Practice appeared in Gideon's CrossingFlashpoint.
Judge Isabel Hernandez from Miss Match appeared in Boston LegalHead Cases and Chitty Chitty Bang Bang.
St. Elsewhere: Tommy's head
from NBC, CBS, HBO, and UPN
Warren Coolidge from The White Shadow appeared in over twenty episodes of St. Elsewhere. After joining St. Elsewhere, he appeared in Method & RedDa Shootout.
Elliot Carlin from The Bob Newhart Show appeared in St. ElsewhereClose Encounters. (The Bob Newhart Show)
Dr. B. J. Hunnicut from M*A*S*H was mentioned by Dr. Mark Craig on St. ElsewhereSanta Claus Is Dead. M*A*S*H has three spin-offs AfterMASH, W*A*L*T*E*R, and The Fighting Nightingales. Trapper John, M.D. is a spin off of MASH, the film, not the television series.
Dr. Elliot Axelrod from St. Elsewhere is a cousin of Kenny Axelrod from Tattingers. Tattingers was renamed to Nick & Hillary.
Dr. Mark Craig from St. Elsewehere received the Cushing Left Anterior Descending Artery Award on Samuels and the Kid as did Dr. Kathryn Austin from Chicago Hope on Women on the Verge. (Chicago Hope)
St. Elsewhere has two connections to Oz, the fictional Weigert Medical Corporation and the character R.N. Carol Grace. Oz is connected to Homicide: Life On The Street and The Beat through the fictional children's television program, Miss Sally's Schoolyard.
In the finale of St. Elsewhere, it was revealed the entire series happened in the head of Tommy Westphall, an autistic child. You can choose to ignore the final scene of St. Elsewhere or not.
A crossover between St. Elsewhere and Julia was attempted, however, the Dr. Morton Chegley characters were played by two different actors who have a nearly fifty year age difference so there was NO cross.
The Bob Newhart Show
from CBS and NBC
Elliot Carlin from The Bob Newhart Show appeared in NewhartI Married Dick where he met Dick Louden.
Jerry Robinson from The Bob Newhart Show appeared in BobBetter To Have Loved And Flossed.
Carol Bondurant from The Bob Newhart Show appeared in Murphy BrownAnything But Cured. (Murphy Brown)
The last scene of The Bob Newhart 19th Anniversary Special revealed Dr. Robert Hartley from The Bob Newhart Show dreamt Newhart. During a discussion about the dream with Howard Borden on The Bob Newhart Show 19th Anniversary, Howard mentioned he dreamt he was Roger Healey from I Dream Of Jeannie.
Larry, Darryl, and Darryl from Newhart appeared in CoachLeaving Orlando parts two and three. (Viva Las Vegas)
The Bob Newhart Show came into the above cosmologies through St. Elsewhere, which is supposedly all in the head of Tommy Westphall. So the following could be considered a dream within a fantasy.
Al Floss from The Famous Teddy Z appeared in Murphy BrownAnd the Whiner Is. The cast of Murphy Brown were seen on television in Love & WarA Nation Turns Its Lonely Eyes to You. Murphy Brown from Muphy Brown appeared in InkMurphy's Law.
Meg Tynan from Love & War appeared in Double RushComings and Goings. Jack Stein from Love & War appeared in three episodes of Ink.
Liz Taylor's lost black pearls led to a crossover between The NannyWhere's the Pearls?, Can't Hurry LoveThe Elizabeth Taylor Episode, Murphy BrownTrick or Retreat, and High SocietyThe Family Jewels.
Jim Dial of Murphy Brown appeared in television in The NannyThe Tart with Heart. Sylvia Fine from The Nanny appeared in The Simple LifeThe Other Mother.
Ray Barone of Everybody Loves Raymond appeared in The NannyThe Reunion Show. Everybody Loves Raymond and The King Of Queens had several crossovers.
Doug Heffernan from The King Of Queens and Hilton Lucas from Cosby appeared in BeckerDrive, They Said. Doug Heffernan also appeared in CosbyJudgment Day.
Isaac Washington from The Love Boat appeared in King of QueensTaste Buds. (The Love Boat)
Viva Las Vegas
from ABC and ITV
Grace Under FireVegas, CoachViva Las Ratings, The Drew Carey ShowDrew Gets Married (The Drew Carey Show), and EllenSecrets & Ellen had characters in Las Vegas on the same night with the following crossover characters.
Luther Horatio Van Dam from Coach and Drew Carey from The Drew Carey Show appeared in Grace Under FireVegas.
Drew Carey and Mimi from The Drew Carey Show and Paige Clark and Spence Kovak from Ellen appeared in CoachViva Las Ratings.
Grace Kelly from Grace Under Fire, Luther Horatio Van Dam from Coach, Paige Clark and Spence Kovak from Ellen appeared in The Drew Carey ShowDrew Gets Married.
Grace Kelly from Grace Under Fire and Drew Carey from The Drew Carey Show appeared in EllenSecrets & Ellen.
Ellen was originally These Friends Of Mine.
Mr. Roper from Three's Company appeared in EllenRoommates. Three's Company spun off The Ropers and Three's A Crowd. Three's Company is a non-contiguous spin-off of Man About the House which has two spin-offs, George and Mildred and Robin's Nest.
The Drew Carey Show
from ABC, NBC, CBS, TNT, and UPN
Detective James Martinez from NYPD Blue appeared in The Drew Carey ShowNew York and Queens. Buck Naked from Hill Street Blues, which had one spin-off Beverly Hills Buntz, appeared in several episodes of NYPD Blue. Lt. Howard Hunter from Hill Street Blues appeared in Cop RockCop-a-Felliac; Victor Sifuentes and Abby Perkins from L.A. Law appeared in Cop RockPotts Don't Fail Me Now. Eli Levinson and Denise Iannello from Civil Wars were also on L.A. Law. John Irvin from NYPD Blue appeared in Public Morals.
The Drew Carey ShowUp on the Roof has Drew Carey watching Tool Time from Home Improvement.
Mimi Bobeck Carey from The Drew Carey Show appeared in Two Guys, a Girl and a Pizza Place, retitled to Two Guys and a Girl, Two Guys, a Girl and a Psycho Halloween; The HughleysYoung Guns (Sabrina and Steve); and The Norm Show, retitled to Norm, Norm vs. Schoolin'.
Drew Carey appeared in The Geena Davis ShowMomma Bear.
Home Improvement spun off Buddies. Brad Taylor from Home Improvement appeared in Thunder AlleyFirst Date. Several characters from Home Improvement appeared in Soul Man: Tim Taylor on Communion Wine and Convicts, Al Borland on Cinderella and the Funeral, and Brad Taylor on Public Embarrassment and Todd's First Sermon. Revered Mike Weber from Soul Man appeared in Home ImprovementLosing My Religion.
Sabrina and Steve
from ABC, UPN/CW, BET, NBC, CBS, Nick at Nite, and Netflix
On the same night, Maya Wilkes from Girlfriends appeared in MoeshaThat's My Mama, Darryl Hughley from The Hughleys appeared in The ParkersWho's Your Mama?, Nikki Parker from The Parkers appeared in The HughleysForty Acres and a Fool, and Niecy Jackson from Moesha appeared in GirlfriendsOld Dog. The Parkers is a spin-off of Moesha. Girlfriends spun off The Game. Hakeem Campbell and Niecy Jackson from Moesha appeared in CluelessProm Misses, Prom Misses.
Sabrina Spellman from Sabrina, the Teenage Witch appeared in CluelessMr. Wright, Boy Meets WorldThe Witches of Pennbrook and No Guts, No Cory, Teen AngelOne Dog Night, and You WishGenie Without a Cause.
Steve Urkel from Family Matters, a spin-off of Perfect Strangers, appeared in Full HouseOl' Brown Eyes and Stephanie Gets Framed; Step by StepThe Dance and A Star Is Born; MeegoLove and Money and The Truth About Cars and Dogs.
Michelle Tanner of Full House appeared in Hangin' With Mr. CooperHangin' with Michelle.
Full House spun off Fuller House.
MeegoMommy 'n' Meego, an unaired episode, crossed with Gilligan's Island. Gilligan's Island spun off three made-for-television films.
Perfect StrangersGames People Play mentioned Cunningham Hardware in Milwalkee, WI from Happy Days.
Happy Days spun offs Laverne & Shirley, Blansky's Beauties, Mork & Mindy, Out of the Blue, and Joanie Loves Chachi. Happy Days spun-off from an episode of the anthology series Love, American Style. Love, American Style had one spin-off The New Love, American Style.
Andrew 'Squiggy' Squiggman from Laverne & Shirley appeared in Scary Movie. Scary Movie spun off four more films.
Marion Cunningham from Happy Days, Carol Brady from The Brady Bunch (The Love Boat), Elyse Keaton from Family Ties (Leave It to Beaver to cross over), Vanessa Huxtable from The Cosby Show, and Lisa Landry from Sister, Sister appeared in Instant MomNot Your Mother's Day.
The Cosby Show spun off A Different World
Disney Channel Live-Action Universe
from NBC and the Disney Channel
Good Morning, Miss Bliss was sold to NBC and retitled to Saved by the Bell. Saved by the Bell spun-off Saved by the Bell: The New Class and Saved by the Bell: The College Years. Years later, That's So Raven was set in the same high school.
President Richard Martinez from Cory in the House appeared in Hannah MontanaTake This Job and Love It.
Zack and Cody Martin and Marion Moseby from The Suite Life on Deck appeared in I'm in the BandWeasels on Deck.
Austin Moon, Ally Dawson, Trish de la Rosa, and Dez Wade from Austin & Ally appeared in JessieNanny in Miami.
Jessie Prescott and the Rosses from Jessie appeared in Austin & AllyBig Dreams & Big Apples. Jessie also appeared in Good Luck CharlieGood Luck Jessie: NYC Christmas.
Joey and Parker Rooney from Liv and Maddie appeared in JessieJessie's Aloha Holidays with Parker and Joey.
Marion Moseby from The Suite Life on Deck appeared in JessieKarate Kid-tastrophe.
That's So Raven spun off Cory in the House and Raven's Home.
The Suite Life of Zack & Cody spun off The Suite Life on Deck and The Suite Life Movie.
Hannah Montana spun off Hannah Montana: The Movie.
Wizards of Waverly Place spun off Wizards of Waverly Place: The Movie and The Wizards Return: Alex vs. Alex.
That's So Suite Life of Hannah Montana
Zack and Cody Martin and Marion Moseby from The Suite Life of Zack & Cody appeared in That's So RavenCheckin' Out. Raven Baxter from That's So Raven and Hannah Montana from Hannah Montana appeared in The Suite Life of Zack and CodyThat's So Suite Life of Hannah Montana.
Wizards on Deck with Hannah Montana
Zack and Cody Martin, London Tipton, Bailey Pickett, and Marion Moseby from The Suite Life on Deck appeared in Wizards of Waverly PlaceCast-Away (to Another Show) and Hannah MontanaSuper(stitious) Girl. Hannah Montana and Lola Luftnagle from Hannah Montana appeared in The Suite Life on DeckDouble-Crossed.
Disney Channel's Monstober 2015
For Disney Channel's Monstober 2015, seven series participated in the event.
Logan Watson and Delia Delfano from I Didn't Do It appeared in JessieThe Ghostest with the Mostest.
Austin Moon and Ally Dawson from Austin & Ally appeared in Girl Meets WorldGirl Meets World: Of Terror 2.
Trish de la Rosa and Dez Wade from Austin & Ally appeared in I Didn't Do ItThe Bite Club.
Emma and Zuri Ross from Jessie appeared in K.C. UndercoverAll Howls Eve.
Riley Matthews and Lucas Friar from Girl Meets World appeared in Best Friends WheneverCyd and Shelby's Haunted Escape.
Ernie and Judy Cooper from K.C. Undercover appeared in Austin & Ally.
Cyd Ripley and Shelby Marcus from Best Friends Whenever appeared in Liv and MaddieHaunt-A-Rooney.
Charlie's Angels Love Boats
This section and The Love Boat are not officially part of the Westphall universe yet.
Charlie's Angels spun off two films and a non-contiguous television series also named Charlie's Angels. Dan Tanna from Vega$ appeared in Charlie's AngelsAngels in Vegas. The entire cast from The Love Boat appeared in Charlie's AngelsLove Boat Angels.
The Love Boat
The Love Boat spun off a reunion film called The Love Boat: A Valentine Voyage and The Love Boat: The Next Wave.
On 22 November 1980 Love BoatSecretary to the Stars story continued on Fantasy IslandThe Love Doctor. Fantasy Island spun off Fantasy Island (1998).
Betty and Margaret Anderson from Father Knows Best; June, Wally, and Beaver Cleaver from Leave It to Beaver (Leave It to Beaver to cross over); and Mike and Carol Brady from The Brady Bunch (Hooterville) all appeared in the final episode of The Love BoatWho Killed Maxwell Thorn?.
Julie McCoy, Doctor Adam Bricker (Doc), Isaac Washington, and Vicki Stubing from The Love Boat appeared in MartinGoin' Overboard.
Leave It to Beaver to cross over
from CBS, ABC, Disney Channel, FOX, NBC, and The WB
Leave It to Beaver spun off Still the Beaver which was renamed The New Leave It to Beaver. (I'm not home!) Eddie Haskell from Leave it to Beaver appeared in Parker Lewis Can't LoseFather Knows Less. Before Eddie Haskell's appearance, Bud Bundy of Married with Children appeared in Parker Lewis Can't LoseMusso & Frank. After Eddie Haskell's appearance, Andrew Keaton of Family Ties appeared in Parker Lewis Can't LoseCivil Wars.
Married with Children spun off Top of the Heap that spun off Vinnie & Bobby. Marcy Rhoades D'Arcy from Married with Children appeared in NikkiTechnical Knockup. Father Guido Sarducci appeared in Married with ChildrenRequiem for a Dead Briard. (Father Guido Sarducci)
Family Ties spun off The Art of Being Nick. Steven and Andrew Keaton of Family Ties appeared in Day by DayTrading Places. Alex P. Keaton of Family Ties was mentioned on Spin CityGoodbye: Part 1. Paul Lassiter from Spin City appeared in Something So RightSomething About the 'Men' in Menstruation. Spin CityInternal Affairs ended with a segue into Sports Night.
from CBS and ABC
The Beverly Hillbillies, Petticoat Junction, and Green Acres shared a large number of characters crossing over, most notably the character Sam Drucker who was a regular on Petticoat Junction and Green Acres. Granny Daisy Moses from The Beverly Hillbillies appeared in Mister EdLove and the Single Horse. (I'm not home!) Colonel Hogan of Hogan's Heroes was mentioned in Green AcresWings Over Hooterville. (Holy defenestration, Batman!)
The Beverly Hillbillies spun off The Return of the Beverly Hillbillies. Green Acres spun off Return to Green Acres.
Hank Thackery, a minor character from Petticoat Junction, may be the same Thackery on The Brady BunchThe Possible Dream. The Brady Bunch spun off The Brady Bunch Hour, The Brady Girls Get Married, The Brady Brides, A Very Brady Christmas, and The Bradys.
Father Guido Sarducci
Father Guido Sarducci, played by Don Novello appeared first on Saturday Night Live. He then appeared in Square PegsPac Man Fever, Tales of the City, BlossomKiss and Tell, Casper, Married with ChildrenRequiem for a Dead Briard, and Unhappily Ever AfterExorcising Jennie.
All in the Family resulted in a total of six other series. Edith Bunker's cousin, Maude Findlay received her own series, Maude. The Bunker's neighbors, George and Louise Jefferson, spun off to their own show, The Jeffersons. All in the Family spun off Archie Bunker's Place. Archie and Edith Bunker's daughter, Gloria divorced her husband and received her own series, Gloria. The Bunker's house appeared with new occupants many years later in 704 Hauser.
Florida Evans of Maude spun off to her own series, Good Times. The series Hanging In is considered a spin-off of Maude, however its stories are not connected to this continuity. Also, Barbara Rhoades played Maggie Gallagher on Hanging In and Maggie Chandler on Soap. Because Gallagher ≠ Chandler, there was no crossover. Soap spun off Benson.
Florence Johnston of The Jefferson's briefly had her own series, Checking In. George Jefferson appeared in the pilot of E/R. The Jeffersons appeared in the finale of The Fresh Prince of Bel-Air along with Philip Drummond and Arnold Jackson-Drummond of Diff'rent Strokes.
Hilary Banks of The Fresh Prince of Bel-Air appeared in Out All NightThe Great Pretender and BlossomWake Up Little Suzy. Carlton and Ashley Banks, also from The Fresh Prince of Bel-Air, appeared in In the HouseDog Catchers.
Mrs. Garrett of Diff'rent Strokes spun off to The Facts of Life. Diff'rent Strokes and Hello, Larry shared three crossover episodes The Trip, Feudin' and Fussin', and Thanksgiving Crossover on both series. (I'm not home!) Arnold Jackson-Drummond made an appearance on Silver SpoonsThe Great Computer Caper.
If Greg Morris appeared in The Jeffersons three-part Mission Incredible as his character Barney Collier from Mission: Impossible, this continuity would cross with Lucy's Diagnosis.
Ghostbuster meets Casper
Dr. Raymond Stantz, played by Dan Aykroyd, from Ghostbusters also appeared in Casper. Ghostbusters spun off Ghostbusters II and the non-contiguous Ghostbusters (2016). Casper spun off two prequels: Casper: A Spirited Beginning and Casper Meets Wendy.
from CBS and NBC
Doctor Phillip Waters from Chicago Hope appeared in Picket FencesRebels with Causes. Douglas Wambaugh from Picket Fences appeared in Chicago HopeSmall Sacrifices.
Picket FencesAway In A Manger referenced Delta Glen and events of The X-FilesRed Museum, which took place in Delta Glen. (The X-Files Xs)
Doctor Jeffrey Geiger from Chicago Hope accepted a heart from a victim on Homicide: Life on the StreetA Doll's Eyes. (Homicide and John Munch)
Doctors Phillip Waters, Keith Wilkes, and Diane Grad from Chicago Hope appeared in Early EditionMum's the Word. Sammo Law from Martial Law appeared in Early EditionPlay It Again, Sammo. Martial LawHonor Among Strangers continues in Walker, Texas RangerThe Day of Cleansing. Walker, Texas Ranger spun off Sons of Thunder.
Kelly Connell played Carter Pike on Picket Fences and C. Peck on Harry's LawOnward and Upward. Because Pike ≠ Peck, there was no crossover.
Homicide and John Munch
from NBC, FOX, CBS, TF1 (France), NTV (Russia), ITV (United Kingdom), UPN, HBO, USA Network, and Netflix
While the character Detective John Munch was on Homicide: Life on the Street there were three crossovers with Law & Order. Law & OrderCharm City continued in Homicide: Life on the StreetFor God and Country. Law & Order was followed by Homicide: Life on the Street in the episodes Baby, It's You and Sideshow on both series. Detective John Munch transferred to Law & Order: Special Victims Unit.
Law & Order and its three spin-offs based in New York city use the fictional newspaper The New York Ledger from Deadline. Exiled is the only film to spin off from Law & Order. Four spin offs are foreign adaptations, one in Paris, France; two in Moscow, Russia; and one in London, the United Kingdom. Law & Order: Los Angeles lasted only one season.
Doctor Elizabeth Olivet from Law & Order appeared in New York UndercoverSmack Is Back, and Doctor Emil Skoda from Law & Order appeared in New York UndercoverMob Street.
White Detective John Munch was on Homicide: Life on the Street he appeared in The X-FilesUnusual Suspects. (The X-Files Xs) After he moved to Law & Order: Special Victims Unit, he appeared in The BeatThey Say It's Your Birthday, Arrested DevelopmentExit Strategy (Wilde Community Arrested), and The WireTook. In Luther's fifth episode of the first season, John Luther mentions John Munch of Law & Order: Special Victims Unit.
The X-Files used the Morley cigarettes which first appeared in Beveryly Hills 90210 and look similar to Marlboro.
Special Victims Unit in Chicago
Erin Lindsay from Chicago P.D. appeared in Law & Order: Special Victims UnitComic Perversion. On the same night, Odafin 'Fin' Tutuola and Amanda Rollins from Law & Order: Special Victims Unit appeared in Chicago P.D.Conventions.
The following year starting with Chicago FireNobody Touches Anything, continued on Law & Order: Special Victims UnitChicago Crossover, and ended on Chicago P.D.They'll Have To Go Through Me.
Another three way crossover started with Chicago FireWe Called Her Jellybean, continued on Chicago P.D.The Number of Rats, and ended on Law & Order: Special Victims UnitDaydream Believer.
Law & Order: Special Victims UnitNationwide Manhunt ends on Chicago P.DThe Song of Gregory William Yates.
The Wilde Oil company from Running Wilde appeared in CommunityThe Psychology of Letting Go. The Bluth Company from Arrested Development appeared in Running WildeThe Pre-Nup.
The airline on FringeThe Dreamscape is called Oceanic Air, the same airline flown by Richard and Alexis Castle on CastleIn Plane Sight. On FringeFirefly, Doctor Walter Bishop says he is friends with Doctor Lawrence Jacoby from Twin Peaks, Bishop is wearing the same 3D glasses that Jacoby wears. (good reason)
Twin Peaks spun off Twin Peaks: Fire Walk with Me and a 2017 revival with the same name. Dr. Jacoby from Twin Peaks appeared on General Hostpital. Red box Morley cigarettes appeared in Part 5 of the revival.
General Hostpital is part of the ABC Soap Opera Universe that includes ten series. I am not going to try to unravel all of the crossovers between them.
General Hospital spun off The Young Marrieds, Port Charles, and General Hospital: Night Shift.
One Life to Live
All My Children
Loving spun off The City.
Red box Morley
from various networks
Red box Morley cigarettes from Beverly Hills, 90210The Back Story can be seen in the following series. Only the first appearance is listed.
Beverly Hills 90120 spun off Melrose Place and 90210. Melrose Place spun off Models, Inc. and Melrose Place (2009).
ERBrothers and Sisters and Third WatchUnleashed crossed when Doctor Susan Lewis on ER got a call from her sister which prompts her to go to New York where she meets Detective Faith Yokas of Third Watch. Doctor Susan Lewis of ER and Detective Faith Yokas of Third Watch are in both episodes.
Third WatchIn the Family Way and Medical InvestigationHalf Life cross when an outbreak of Marburg brings the NIH team to New York. Doctors Stephen Connor and Natalie Durant from Medical Investigation appeared in Third Watch and Detective Faith Yokas, Carlos Nieto, and Holly Levine from Third Watch appeared in Medical Investigation.
Detective Faith Yokas is the only character to have been on all three series.
from CBS and FOX
CSI: Crime Scene Investigation has three spin-offs CSI: Miami, CSI: NY, and CSI: Cyber. The CSI: Crime Scene Investigation episode Who and What concluded in the Without a Trace episode Where and Why. Detective Scotty Valens from Cold Case appeared in CSI:NYCold Reveal.
CSI: Crime Scene InvestigationThe Lost Girls and BonesThe Woman in the Sand both mention the fictional Tangiers hotel. Bones spun off The Finder.
BonesThe Resurrection in the Remains crossed over with Sleepy HollowDead Men Tell No Tales.
There was no crossover when Jon Cryer, Charlie Sheen, and Angus Jones from Two and a Half Men appeared as themselves on CSI: Crime Scene InvestigationTwo and a Half Deaths. (people not considered, Two and a Half)
Criminal Minds spun off Criminal Minds: Suspect Behavior and Criminal Minds: Beyond Borders.
from FOX and A&E
Prison Break spun off Prison Break: Proof of Innocence and Breakout Kings.
The blue meth from Breaking Bad appeared in The Walking DeadBloodletting. Breaking Bad spun off Better Call Saul. The Walking Dead spun off Fear the Walking Dead, however it is not contiguous with The Walking Dead.
from ABC, Showtime, FOX, and NBC
Happy Time Temp Agency from Dead Like Me was mentioned on Pushing DaisiesBzzzzzzzzz!. Dead Like Me spun off Dead Like Me: Life After Death.
Marianne Marie Beetle from WonderfallsMuffin Buffalo appeared in Pushing DaisiesComfort Food and Mockingbird Lane.
Gretchen Speck-Horowitz from Wonderfalls appeared in HannibalAmuse-bouche under her maiden name Gretchen Speck.
from FOX, Showtime, and FX
24 spun off 24: Live Another Day and 24: Legacy. 24 uses a fake news company known as CNB. CNB has appeared in Homeland "The Star" and in Tyrant second season. Howard Gordon worked on 24 and helmed the latter two series.
Eureka and Warehouse 13 had three crosses. Douglas Fargo from Eureka appeared in Warehouse 1313.1. Claudia Donovan from Warehouse 13 appeared in EurekaCrossing Over. Douglas Fargo also appeared in Warehouse 13Don't Hate the Player.
Dr. Vanessa Calder, who recurred on Warehouse 13, appeared in AlphasNever Let Me Go.
from The WB; FOX; NBC; and Showtime
Weyland-Yutani, the greedy corporation from the Alien series, is mentioned as a client of the evil law firm Wolfram & Hart on AngelHarm's Way. Weyland-Yutani's logo and an Imperial shuttle from Star Wars appeared in FireflySerenity. A Holnist patch from The Postman can be seen on the shoulder of a dock worker on the Firefly film Serenity.
A M41A Pulse Rifle and USCM Smart Gun from Aliens appeared in Soldier. The soldier's service record shows he fought in the battles of Tannhauser Gate and Shoulder of Orion from Blade Runner, also the spinners from Blade Runner appeared in Soldier. Blade Runner is followed by Blade Runner 2049.
Alien vs. Predator series serves as a prequel to the Alien series and a sequel to the Predator series. (The film Predators is not part of the Alien vs. Predator series.)
Buffy Summers from Buffy the Vampire Slayer, which spun off Angel, worked at the Doublemeat Palace owned by Guy Halveston, whose murder was investigated by Andy Barker, P.I. in Fairway, My Lovely. The Doublemeat Palace was previously mentioned in DexterTruth Be Told.
from BBC One, Two, and Three; CBBC; ITV; Fox; Disney; Nickelodeon; and TNT
The TARDIS from Doctor Who appeared in Red DwarfMarooned in the hanger of the ship, Chelmsford 123Arrivederci Roma, SherlockThe Hounds of Baskerville, and The LibrariansAnd the Final Curtain where Doc Brown's DeLorean from Back to the Future also appeared.
A Narcissus escape shuttle built by Weyland-Yutani from Alien, a Klingon Bird of Prey from Star Trek, and the Eagle from Space: 1999 appeared in Red DwarfPsirens in a shipyard of derelict ships.
Gallifrey from Doctor Who was mentioned by location and name on Rangers Lost GalaxyGreen Courage. Prior to that, the Teenage Mutant Ninja Turtles from Ninja Turtles: The Next Mutation appeared in Power Rangers in SpaceShell Shocked.
Arthur Dent from The Hitchhiker's Guide to the Galaxy was mentioned in Doctor WhoThe Christmas Invasion. Doctor Who has five spin-offs.
Note: The Power Rangers and Teenage Mutant Ninja Turtles are so convoluted, I'm not going to try to detangle them.
R2-D2 from Star Wars appeared in Star Trek (2009) and Star Trek Into Darkness.
The sarlacc from Star Wars: Return of the Jedi was mentioned in Once Upon a Time in WonderlandForget Me Not. (Lost in Alias)
The Montecito Resort and Casino
from NBC, ABC, and BBC Two
If you watched Crossing Jordan you probably already know that it crossed over with Las Vegas. Crossing JordanWhat Happens in Vegas Dies in Boston continued in Las VegasTwo of a Kind. Crossing JordanLuck Be a Lady continued in Las VegasDouble Down, Triple Threat. There were episodes of each series which had appearances by characters from the other which did not share a story line with the other that week. Jordan Cavanaugh and Woody Hoyt of Crossing Jordan appeared in Las VegasHistory of Violins. Danny McCoy of Las Vegas appeared in Crossing JordanCrazy Little Thing Called Love.
When a network has a series which is set in a casino, every time another series needed one, you can guess where they went, in this case the Montecito Resort and Casino in Las Vegas.
The Passions 20 and 23 May 2005 episodes were set in the Montecito with Mary Connell from Las Vegas appearing. Before characters from Passions gambled at the Montecito, Dr. Bombay from Bewitched appeared in Passions on 17 September 1999. Bewitched spun off Tabitha.
On MediumMethod to His Madness, Allison Dubois was dreaming about a person who was gambling at the Montecito.
On Las VegasThe Story Of Owe, the fictional company Dunder-Mifflin from The Office (U.S.) is mentioned. After the the people from Dunder-Mifflin went to the Montecito off screen, David Brent from The Office (U.K.) appeared in The Office (U.S.) The Seminar. The Sergio Georgini fashon line from The OfficeParty (U.K.) appeared in It's Always Sunny in PhiladelphiaA Very Sunny Christmas.
On HeroesCollision, the characters Hiro Nakamura and Ando Masahashi gamble at the Montecito. Heroes spun off Heroes Reborn.
On Knight Rider, the 2008 film, the characters Mike Traceur and Sarah Graiman met in the Montecito. Before Mike and Sarah met at the Montecito, the original Knight Rider series two part episode Mouth of the Snake introduced the character David Dalton who would go onto his own series Code of Vengeance.
Are witches heroes? Are heroes witches? Is the fictional Allison Dubois a witch, hero, or both?
Lost in Alias
from ABC and NBC
Lost had two minor crossovers with Alias. The first was the fictional band called Driveshaft who were introduced on Lost and got a minor mention on AliasAuthorized Personnel Only part 2. On AliasA Clean Conscience, the flight which got lost in Lost was mentioned.
Oceanic Airlines appeared in LAXSenator's Daughter, FlashForwardNo More Good Days, and Once Upon a TimeThe Stranger. Once Upon a Time spun off Once Upon a Time in Wonderland. Oceanic Airlines flight 815 from Lost was mentioned on ChuckChuck Versus the Helicopter, however the details around its destruction were inaccurate. (good reason)
LostRaised by Another was the first appearance of Gannon Car Rentals. It has since appeared in Nip/TuckConor McMamara, 2026, HeroesThe Fix, and GleeThe New Rachel.
Credit Dauphine, a fictional bank, from Alias appeared in Eli Stone "The Path".
L.A.P.D. Police Sergeant Al Powell makes his first appearance in Die Hard and then again in Die Hard 2. He reappears almost two decades later on ChuckChuck Versus Santa Claus. Die Hard had three more sequels.
You can read more about Oceanic Airlines and find out why some do not cross over with Lost.
Hawaii 5-0 is a remake of Hawaii 5-O and used footage from the original's episode "Wooden Model of a Rat" in the episode "Kalele". While Ed Asner reprised his character August March from the original in the remake, the back story is very different between the series.
Kensi Blye from NCIS: Los Angeles appeared in Hawaii 5-0 "Ka Hakaka Maika'i". G. Callen and Sam Hannah from NCIS: Los Angeles appeared in Hawaii 5-0Pa Make Loa which concluded on NCIS: Los AngelesTouch of Death with Daniel Williams and Chin Ho Kelly from Hawaii 5-0 appearing.
Hetty Lange from NCIS: Los Angeles appeared in ScorpionTrue Colors.
Chin Ho Kelly, Kono Kalakaua, and Kamekona from Hawaii 5-0 appeared in MacGyver "Flashlight". MacGyver is a reboot of the ABC series of the same name.
Hawaii 5-0 got a mention in Magnum P.I. (2018) I Saw the Sun Rise, then Kamekona from Hawaii 5-0 appeared in From the Head Down.