SFAIK, he guest starred in The Untouchables, The Wild, Wild West, and Batman. ST: TOS, never.
Thanks, terentii. But I got Shatner!
Life doesn’t get any better than that! 
Robert Phillips (“Nice place you have here, Captain!”) in the ***M:I ***episode “The Deal.”
I just discovered that the voice of “Transporter Chief Pitcairn” in “The Cage” (played by Clegg Hoyt*) was dubbed by Bob Johnson, the guy who recorded “Division Seven’s” assignments for the IMF each week: “Your mission, Dan/Jim, should you decide to accept it…”
*Any relation to John “Dr Boyce” Hoyt, I wonder? 
As an aside, the IMDb notes for “The Cage” say the unnamed transporter technician was one of three Starfleet personnel ever to be seen wearing corrective eyeglasses. In what episode(s) were the other two?
Jon Lormer (“Dr. Theodore Haskins” in “The Cage,” “Tamar” in “Return of the Archons,” and the “Old Man” in “For the World Is Hollow and I Have Touched the Sky”) in the ***MTM ***episode “Mary and the Sexagenarian.”
Ed McCready (the barber in “Spectre of the Gun,” inter alia) and Bruce Watson (“Crewman Green”) in the ***M:I ***episode “Leona.”
I watched more of the 77 Sunset Strip episode, and saw Shatner chewing the scenery, also the present day Shatner on a commercial. Double points!
Ray Walston (“Groundskeeper Boothby”) in the M:I episode “TOD-5.”
Bill “JT Kirk” Shatner and Charles “Adam” Napier in the M:I episode “Cocaine.”
James B Sikking (“Captain Styles”) as an Underground agent in the HH episode “The Big Broadcast.”
Peter Mark Richmond (“Ralph Offenhouse”) and Joseph Bernard (“Tark”) in the ***M:I ***episode “Underground.”
I remember that guy, but I can’t think of anyone else other than Kirk with his specs in TWOK.
Rhodes Reason (“Flavius”), David Brian (“John Gill”), and Walter Edmiston (multiple voices) in the ***M:I ***episode “Movie.”
Nancy “Nona” Kovack as “Sheila” in the pilot episode of Bewitched.
Just saw Close Encounters of the Third Kind again - it holds up pretty well - and of course noticed Terri Garr as the hero’s baffled wife.
Joseph “Galt” Ruskin (again!) and John “Commissioner Ferris” Crawford in the ***M:I ***episode “The Puppet.”
Rene “Odo” Auberjonois as “Professor Tewksbury” in the ***Frasier ***episode “Frasier’s Edge.”
He was also in that lawyer show with Shatner.
Julie “Lt Palamas” Parrish and Johnny “Constable” Haymer (“Aye, m’Lord. Called 'im ‘Bones,’ 'e did!”) in the HH episode “Kommandant Gertrude.”
Gary Lockwood (“Gary Mitchell”) and Jason Evers (“Rael”) in the ***M:I ***episode “The Question.” This episode was written by Stephen Kandel, who wrote the “Harry Mudd” episodes of TOS.