Dame Frances Margaret Anderson, AC, DBE, starred in the Wagon Train episode, The Felizia Kingdom Story, played Vulcan High Priestess T’Lar in The Search for Spock. It is said that someone had to form her hand into the Vulcan “Live long, and prosper” sign.
Leonard Nimoy played a hired killer in the Shennandoah episode, Run Killer, Run.
…And the Doctor says, “I’m a doctor, not a miracle worker”. 
…And Sally Kellerman of* Where No Man Has Gone Before* played the love interest.
Let’s see, I don’t think I’ve posted in this thread yet. In the Starcraft II campaigns, Michael Dorn played a super-powerful deus-ex-machina Ancient One alien, and John Delancy (of course) played a smarmy villain helping the heroes just because it was in his best interest.
The games also included Number Six, from Battlestar Galactica, and Ivanova, from Babylon 5.
Does he ever play anything else? 
Hope this wasn’t posted yet, but Majel Barrett played a society journalist on General Hospital in 1983, covering Celia Quartermaine’s wedding to Grant Putnam.
I am surprised that Dorn and Delancy needed money that badly.
John “Mr Hengist” Fiedler and Peter “Claymare” Brocco in Bewitched’s “Marriage Witches’ Style” (S05 E21).
NB: Lloyd Bochner, who played warlock Franklyn Blodgett in this episode, was considered as a replacement for Leonard Nimoy when he was holding out for more money after the first season of*** Star Trek***.
You say that like video game voice acting is a low rent gig. Twenty years ago, that’d be mostly true, but in the modern game market? Star Craft II sold 1.8 million units within 48 hours of launch - at ~$60 a copy, that makes it more profitable in its first two days than any Star Trek movie starring the original or TNG casts. (The reboots, naturally, made buckets more money than any of the “good” Star Trek movies.)
Michael Dorn, in particular, is an accomplished voice actor who’s worked extensively in video games, with 27 different game credits listed at MobyGames.com. John de Lancie has sixteen. And they’ve got good company!
Patrick Stewart’s got twenty-five video game credits.
Wil Wheaton has twenty-four.
Brent Spiner has six.
Jonathan Frakes has five.
Marina Sirtis has five.
LeVar Burton has three.
Denise Crosby has two.
Gates McFadden has two, and is the only TNG actor on this list whose credits are limited to Star Trek titles.
Also, to round things out, Shatner has twelve, Nimoy seven, and Kelley five.
I just saw Majel Barrett in an ep of “77 Sunset Strip.” She played a housekeeper/cook named ‘Ilse,’ who spoke with a not particularly good German accent. And Mrs. Howell was her employer! (But all of Schafer’s roles were pretty much Mrs. Howell.)
Darn, I thought I had seen all of them.
Korob, of Catspaw, in the Have Gun Will Travel episode, “Return of the Lady”.
A mean SOB, as usual.
I just rewatched Dagger of the Mind the other week, then at the end of the week High Plains Drifter, spotting Marianna Hill, who Memory Alpha assures me had all sorts of run ins with other Trek alumni.
Boris Lee Krutonog, “Oleg’s dad,” as noted in the thread for The Americans:
Ken Lynch, the mining engineer from Devil in the Dark, in the Have Gun, Will Travel episode, The Long Hunt.
The previous episode of HGWT, The Monster of Moon Ridge, was written by Gene Roddenberry.
No, it was Anthony Caruso who played Jose, Bella Oxmyx from A Piece of the Action.
A slight cheat, but Holy Mackerel!:
I was watching “TOS: Court Martial;” haven’t seen Joan Marshall (Areel Shaw) in just about anything else, so I IMDBed her. Lots of stuff prior to ST:TOS. Then there was a listing for “The Munsters,” 
from 2004 . Ms Shaw passed on in 1992 . Dig it: JM played Phoebe Munster in the original pilot (Phoebe became Lily later on), but was let go because she was too similar to Morticia Addams from that other show. A SECOND pilot was filmed that included Yvonne DeCarlo as (now) Lily. And the original original pilot was released (?) in 2004.* I haven’t seen it yet (drool, drool) so there’s your cheat. I beg forgiveness.
*Confused? You won’t be after this episode of, Soap!
Anthony Caruso, Bella Oxmyx from A Piece of the Action playing a US Army colonel in the Whirlybirds episode of 1959, Egg Code.
BTW, he steals the girl from one of the Whirlybird guys, PT.
:dubious:
Just caught an episode of Batman with two Trek actors; Elisha Cook, Jr., who had been in Court Martial, and Leslie Parrish, who would go on to be in Who Mourns for Adonais? And all of those shows were from 1967.
And it was the last episode of Batman without Yvonne Craig, who would go on to be in Whom Gods Destroy.
I was watching an Alias Smith and Jones rerun today when I spotted Susan Oliver, Vina from The Cage.