If you mean T'Pol on Star Trek Enterprise then it was Jolene Blacock. It says it on the info guide and opening credits.
Arvo Katajisto has: Played Romulan in "Star Trek: The Next Generation" in 1987. Played Devidian Man in "Star Trek: The Next Generation" in 1987. Played Ensign Torigan in "Star Trek: The Next Generation" in 1987. Played Romulan Guard in "Star Trek: The Next Generation" in 1987. Played Castle Courtier in "Star Trek: The Next Generation" in 1987. Played Klingon in "Star Trek: The Next Generation" in 1987. Played Security Guard in "Twin Peaks" in 1990.
Kate Mulgrew played Captain Kathryn Janeway in Star Trek Voyager.
Debra Dilley has: Played Klingon Pilgrim in "Star Trek: The Next Generation" in 1987. Played Operations Division Officer in "Star Trek: The Next Generation" in 1987. Played Borg in "Star Trek: The Next Generation" in 1987. Played Command Division Officer in "Star Trek: The Next Generation" in 1987. Played Sela in "Star Trek: The Next Generation" in 1987.
In the Star Trek (2009) movie, Jacob Kogan played the child Spock.
Jeri Ryan who played 7 of 9 in Star Trek: Voyager
Frank da Vinci has: Played Soldier at Party in "Star Trek" in 1966. Played Eminiar Guard in "Star Trek" in 1966. Played Transporter Operator in "Star Trek" in 1966. Played Vulcan Ceremonial Aide in "Star Trek" in 1966. Played Vulcan Aide in "Star Trek" in 1966. Played Sebastian in "Mission: Impossible" in 1966. Played Lt. Osborne in "Star Trek" in 1966. Played Vinci in "Star Trek" in 1966. Played Lt. Brent in "Star Trek" in 1966. Played Lt. Clifford Brent in "Star Trek" in 1966. Played Guard in "Star Trek" in 1966. Played Security Guard in "Star Trek" in 1966. Played Brent in "Star Trek" in 1966. Played Crewman in "Star Trek" in 1966. Played Capellan Warrior in "Star Trek" in 1966.
Jean Luc Picard appears in the following Star Trek movies:* Star Trek: Generations * Star Trek: First Contact * Star Trek: Insurrection * Star Trek: Nemesis
Jeff Mailhotte has: Played Lt. Sentell in "Star Trek: New Voyages" in 2004. Played Security Officer in "Star Trek: New Voyages" in 2004. Played Sentell in "Star Trek: New Voyages" in 2004. Played Security Oficer in "Star Trek: New Voyages" in 2004. Played Comm. Officer 1 in "Star Trek: New Voyages" in 2004. Played Klingon in "Star Trek: New Voyages" in 2004. Played G.S.S. Conqueror Crew in "Star Trek: Of Gods and Men" in 2007.
Larry Nemecek has: Played himself in "Biography" in 1987. Played Cal Strickland in "Star Trek: New Voyages" in 2004. Played Esterion in "Star Trek: New Voyages" in 2004. Played Tellarite Grolst in "Star Trek: New Voyages" in 2004. Played Mark Dolding in "Star Trek: The Continuing Mission" in 2007. Played himself in "Trek Nation" in 2010. Played himself in "Making It So: Continuing Star Trek - The Next Generation" in 2012. Played himself in "Backyard Blockbusters" in 2012. Played Dr. McCoy in "Star Trek Continues" in 2013. Played himself in "Requiem - A Remembrance of Star Trek: The Next Generation" in 2013. Played himself in "Relativity: The Family Saga of Star Trek - The Next Generation" in 2013. Played himself in "The Green Girl" in 2014.
Eddie Paskey has: Played Policeman in "Ben Casey" in 1961. Played Party Guest in "The Dick Van Dyke Show" in 1961. Played Eminiar Guard in "Star Trek" in 1966. Played Man Taking Suitcase from Safe in "Mission: Impossible" in 1966. Played Lt. Leslie in "Star Trek" in 1966. Played Lt. Ryan in "Star Trek" in 1966. Played Steve in "Mission: Impossible" in 1966. Played Connors in "Star Trek" in 1966. Played Guard in "Star Trek" in 1966. Played Trooper in "Star Trek" in 1966. Played Lt. Leslie in "Star Trek: Deep Space Nine" in 1993. Played Admiral Leslie in "Star Trek: New Voyages" in 2004. Played Lieutenant Leslie in "How William Shatner Changed the World" in 2005. Played himself in "Bring Back... Star Trek" in 2009.
Ed Abbate has: Played Crewman in "Star Trek: New Voyages" in 2004. Performed in "Star Trek: New Voyages" in 2004. Played Lt.Cmdr. Ensign in "Star Trek: New Voyages" in 2004. Played Starfleet Personnel in "Star Trek: New Voyages" in 2004. Played Extra in "Star Trek: New Voyages" in 2004.
Arvo Katajisto has: Played Romulan in "Star Trek: The Next Generation" in 1987. Played Devidian Man in "Star Trek: The Next Generation" in 1987. Played Ensign Torigan in "Star Trek: The Next Generation" in 1987. Played Romulan Guard in "Star Trek: The Next Generation" in 1987. Played Castle Courtier in "Star Trek: The Next Generation" in 1987. Played Klingon in "Star Trek: The Next Generation" in 1987. Played Security Guard in "Twin Peaks" in 1990.
Kate Mulgrew played Captain Kathryn Janeway in Star Trek Voyager.
Walter Koenig played the original Pavel Andreievich Chekov in Star Trek TOS and the first 7 Star Trek movies.
Debra Dilley has: Played Klingon Pilgrim in "Star Trek: The Next Generation" in 1987. Played Operations Division Officer in "Star Trek: The Next Generation" in 1987. Played Borg in "Star Trek: The Next Generation" in 1987. Played Command Division Officer in "Star Trek: The Next Generation" in 1987. Played Sela in "Star Trek: The Next Generation" in 1987.
Tracee Cocco has: Played Ensign Jae in "Star Trek: The Next Generation" in 1987. Played Med Student in "Gross Anatomy" in 1989. Played Lifeguard in "Baywatch" in 1989. Played Antican in "Star Trek: Deep Space Nine" in 1993. Played Cop in Headquarters in "Demolition Man" in 1993. Played Kobheerian in "Star Trek: Deep Space Nine" in 1993. Played Ensign Jae in "Star Trek: Generations" in 1994. Played Nekrit alien in "Star Trek: Voyager" in 1995. Played Club Goer in "Virtuosity" in 1995. Played TV Reporter in "Angel Devoid: Face of the Enemy" in 1995. Played Kobheerian in "Star Trek: Voyager" in 1995. Played Mokra homeworld alien in "Star Trek: Voyager" in 1995. Played Bar Patron in "Barb Wire" in 1996. Played Starfleet Science Officer in "Star Trek: Borg" in 1996. Played Club Goer in "Bulletproof" in 1996. Played Alien Bar Patron in "Star Trek: Klingon" in 1996. Played Ensign Jae in "Star Trek: First Contact" in 1996. Played Ensign Jae in "Star Trek: Insurrection" in 1998.
No, but he was in Star Trek VI: The Undiscovered Country. In it, Michael Dorn played "Colonel Worf", believed to be the grandfather of the Worf character he played on Star Trek: The Next Generation and Star Trek: Deep Space Nine.