Some of these I knew about.
Kirstie AlleyStar Trek II: The Wrath of Khan - 1982
Before she started on "Cheers," Alley was Lieutenant Saavik, a Vulcan recruit on her first mission.
Whoopi Goldberg"Star Trek: The Next Generation" - 1988-1993
Goldberg appeared as Guinan the bartender on TV and in the movie
Star Trek: Generations.
Teri Hatcher"Star Trek: The Next Generation" - 1988
Hatcher played of Lt. Robinson in the episode "The Outrageous Okona" that also featured Joe Piscopo.
Nikki Cox"Star Trek: The Next Generation" - 1989
11-year-old Cox was covered in orange makeup to play the alien Sarjenka in the episode "Pen Pals."
Kim CattrallStar Trek VI: The Undiscovered Country - 1991
Cattrall's role as a turncoat Lt. Valeris was originally written to be Kirstie Alley's character from "Khan."
Ashley Judd"Star Trek: The Next Generation" - 1991
Judd appeared in two episodes as Ensign Robin Lefler, which lead to her first on-screen kiss.
Kirsten Dunst"Star Trek: The Next Generation" - 1993
Dunst was 11 years old when played a telepathic alien named Hedril in the episode "Dark Page."
Sarah Silverman"Star Trek: Voyager" - 1996
The sharp-tongued comedienne played a 20th century alien researcher in a two-part episode.
Vanessa Williams"Star Trek: Deep Space Nine" - 1996
Williams was a native of the "pleasure planet" Risa in the episode "Let He Who Is Without Sin..."
Andy Dick"Star Trek: Voyager" - 1998
This off-kilter comic played a holographic doctor EMH Mark II in the episode "Message in a Bottle".