History IWantYouToMeetAnOldFriendOfMine / LiveActionTV

** [=McGee=]'s sister is played by Sean Murray's stepsistter Troian Bellisarion (who is also series creator Donald Bellisario's daughter)

** McGee's sister is played by Sean Murray's stepsistter Troian Bellisarion (who is also series creator Donald Bellisario's daughter)

** Amazingly, their Cosby Show and Problem Child appearances together occurred 6 years before they even started dating.

** William Shatner appears as himself in the episode "The D&D Vortex" and shares a scene with Penny. Penny's actress, Kaley Cuoco, previously appeared alongside Shatner in commericals for Priceline.

* In ''Series/{{Wings}}'', Tim Daly's real life sister Tyne Daly guest starred as a wealthy woman who wanted Brian as her gigolo.

nci* Creator/BobNewhart's first sitcom wife, Suzanne Pleshette (in ''Series/TheBobNewhartShow''), showed up in the final episode of his second sitcom (''Series/{{Newhart}}''), where it turned out the whole later series (in which he played a New England innkeeper) [[spoiler:was AllJustADream]].

** Kate O'Mara appeared as nefarious Time Lord the Rani opposite Creator/ColinBaker in "[[Recap/DoctorWhoS22E3TheMarkOfTheRani The Mark of the Rani]]". They'd previously co-starred in the drama series ''Series/TheBrothers''.

** ''Series/TheWalkingDead'': Audrey Marie Anderson (Lyla Michaels-Diggle), Creator/EmilyKinney (Brie Larvan), Emma Bell (Emily Nocenti), Creator/Creator/ChadLColeman (Tobias Church), Rutina Wesley (Liza Warner), and Creator/KirkAcevedo (Ricardo Diaz).

* Creator/BobNewhart's first sitcom wife, Suzanne Pleshette (in ''Series/TheBobNewhartShow''), showed up in the final episode of his second sitcom (''Series/{{Newhart}}''), where it turned out the whole later series (in which he played a New England innkeeper) [[spoiler:was AllJustADream]].

* On ''Series/{{NCIS Los Angeles}}'', Hetty goes to an "old friend" for assistance with an issue involving the Marines; a long past is implied between the two of them, although it hasn't come up before. The character is Sarah "Mac" MacKenzie from ''Series/{{JAG}}'', the show that originally launched parent show Series/{{NCIS}} and thus all the spin-offs. (co-star Harm makes an appearance in the same episode, but not as an example of this trope).

* In the S1 finale of the (surprisingly watchable) Creator/CourteneyCox Arquette vehicle ''Series/{{Dirt}}'', Creator/JenniferAniston turns up as a rival tabloid editor. [[GirlOnGirlIsHot They actually kiss]], [[DistractedByTheSexy in front of some people at the newsdesk]]

** ''Series/{{The Tomorrow People 2013}}'': Creator/RobbieAmell (ComicBook/{{Firestorm}}) and Creator/PeytonList (Golden Glider).

* ''Series/ThatsSoRaven'' once had a guest appearance by Kirsten Storms, whose best friend Creator/RavenSymone played in the first ''Film/{{Zenon}}'' movie. Ironically, Storms portrayed an AlphaBitch in this episode.

* ''Series/{{Letterkenny}}'': Prior to portraying Wayne in this 2016 comedy, Jared Keeso played Constable Nick Chartier in the 2014 drama ''19-2''. Dan Petronijevic, who played JM Brouillard in 19-2, has a recurring role as McMurray in Letterkenny. In the season 3 finale, Adrian Holmes who played Keeso's co-star Constable Nick Barron in 19-2 is introduced as Gail and Rosie's male cousin Bradley.

* Creator/ScottBakula also was imprisoned by his ''Series/QuantumLeap'' sidekick Creator/DeanStockwell in the ''Series/StarTrekEnterprise'' episode "[[StarTrekEnterpriseS01E21Detained Detained]]".

** Several ''Series/TheWire'' alumnae have appeared on the show. Those who appeared so far are Creator/ChadLColeman (Tyreese), Laurence Guillard, Jr. (Bob Stookey) and Creator/SethGilliam (Fr. Gabriel Stokes), all in major roles.
** Quite a number of ''Series/The100'' cast have appeared both in the show and [[Series/FearTheWalkingDead the spin-off]]. Those who appeared so far are Creator/AlyciaDebnamCarey (Alicia Clark), Creator/BrendaStrong (Ilene Stowe), and Creator/NadiaHilker (Magna).

** Averted in Creator/PeterCapaldi's first season as the Doctor, his ''Series/TheThickOfIt'' co-star Chris Addison had a recurring role as Missy's henchman. The two had no prior onscreen relationship, and never even met face to face. Rebecca Front appeared in "[[Recap/DoctorWhoS35E7TheZygonInvasion The Zygon Invasion]]" and Tony Gardner appeared in "[[Recap/DoctorWhoS36E7ThePyramidAtTheEndOfTheWorld The Pyramid at the End of the World]]".

** In another episode, entitled "Family Ties", Creator/JasonBateman's character meets a woman he thinks is his long-lost sister but turns out to be a prostitute. She's played by his actual sister, Justine Bateman, who's most famous for her role on ''Series/FamilyTies''.

* The ''Series/{{Buffy the Vampire Slayer}}'' fifth season opener was "[[{{Recap/BuffyTheVampireSlayerS5E1BuffyVsDracula}} Buffy vs. Dracula]]", billed as a battle of the titans. It was a little undercut by Dracula being played by Creator/SarahMichelleGellar's old flame from ''Series/AllMyChildren'', Rudolf Martin.

** Kate O'Mara appeared as nefarious Time Lord the Rani opposite Creator/ColinBaker in "[[Recap/DoctorWhoS22E3TheMarkOfTheRani The Mark of the Rani]]". They'd previously costarred in the drama series ''Series/TheBrothers''.

** Tennant's ''Series/{{Blackpool}}'' co-star Creator/DavidMorrissey appeared in "[[Recap/DoctorWhoS30E14TheNextDoctor The Next Doctor]]".

** Several ''Series/TheWire'' alumnae have appeared on the show. Those who appeared so far are Creator/ChadLColeman (Tyreese), Laurence Guillard, Jr. (Bob Stookey) and Seth Gilliam (Fr. Gabriel Stokes), all in major roles.

* ''Series/{{CSINY}}'' had two. One of Creator/GarySinise's costars from the miniseries of ''Series/TheStand'' appeared in the season one episode "'Night Mother," though they had only one brief scene together. More prominently was Mac's boss Sinclair played by Creator/MykeltiWilliamson, who starred alongside Gary as Bubba in ''Film/ForrestGump''.

** Averted in Creator/PeterCapaldi's first season as the Doctor, his ''Series/TheThickOfIt'' co-star Chris Addison had a recurring role as Missy's henchman. The two had no prior onscreen relationship, and never even met face to face. His second season saw another castmember, Rebecca Front, appear in "[[Recap/DoctorWhoS34E7TheZygonInvasion The Zygon Invasion]]".

** From ''Series/TheWalkingDead'': Creator/SonequaMartinGreen, Brighton Sharbino, and Creator/MichaelRaymondJames.

* ''Series/SpinCity's'' Richard Kind, Michael Boatman, Alan Ruck, Creator/BarryBostwick, Alexander Chaplin, Heather Locklear and of course Creator/MichaelJFox have all appeared in Bill Lawrence's ''next'' show, ''Series/{{Scrubs}}''.