Theresa Lee (Terry) Farrell was born November 19th, 1963 in Cedar Rapids, Iowa, the daughter of Kay Carol Christine and Edwin Francis Farrell, Jr.

In her junior year of high school, the almost six-foot-tall Farrell submitted her image to the Elite modelling agency in New York City. Shortly after, at the age of 16, she was invited to New York City and, within two days of arriving, had an exclusive contract with Mademoiselle. She went on to appear on the covers of the Italian and German editions of Vogue and was also featured in numerous editorials for American Vogue.

After 18 months of modelling, she studied acting while still modelling on the side. Her first major roles were in the short-lived 1984 television series Paper Dolls, playing a model, and in the feature film Back to School with Rodney Dangerfield.

In 1989, she began studying acting with Stella Adler and appeared in several guest-starring roles in series, including Quantum Leap and The Cosby Show. In 1992, she played Cat in a second pilot for a U.S. version of Red Dwarf, which was not picked up.

Soon after the Red Dwarf USA project folded, she was offered a lead role in Star Trek: Deep Space Nine as Jadzia Dax, the space station's Starfleet science officer, a character from an alien species known as the Trill, who is host to a 300-year-old symbiont and can draw upon the memories and knowledge of the symbiont's seven previous hosts.

When Farrell decided to leave the show at the end of the sixth season, Paramount killed off Farrell's host character though continued the symbiont character in a new Dax host, played by Nicole DeBoer as Ezri Dax.

Farrell then co-starred on Paramount's television comedy series Becker. She played Regina (Reggie) Kostas, foil and love interest to Ted Danson's John Becker, for four years and 94 episodes before she was replaced.

Farrell also provided the voice of Six of One in the animated short film Tripping the Rift, which eventually became a Sci-Fi Channel TV series with other actors providing the voice of Six. First released independently on the Internet, Tripping the Rift originally featured Patricia Beckmann as the voice of Six and was replaced by Farrell's voice for an episode of the Sci-Fi Channel's short film series Exposure, in which Farrell was the guest host.

Farrell retired in 2002 after marrying actor Brian Baker. They divorced in 2015 and Farrell played a role in the web-released fan film Star Trek: Renegades. She is expected to appear in the same role in episodes of the fan film web series Renegades, which strips mention of Star Trek for legal purposes.

Farrell retired from acting to concentrate on her family. She lived in Hershey, Pennsylvania, with her husband, former Sprint Corporation spokesman Brian Baker (aka. the Sprint Guy) and their son, Max. She enjoys sewing and yoga. Farrell appeared with Baker at the Hershey Area Playhouse in Hershey, Pennsylvania, in production of A. R. Gurney's Love Letters. Farrell and Baker have been divorced since December 2015. In an interview in 2011, she said that she and Deep Space Nine co-star Michael Dorn have always been good friends.

In August 2017, it was reported that she was in a relationship with Adam Nimoy and Farrell confirmed on Twitter that they were engaged. Farrell and Nimoy were married in San Francisco on March 26, 2018, on what would have been Leonard Nimoy’s eighty-seventh birthday.

Film Career:
  • 1986 Back to School
  • 1987 Off the Mark
  • 1992 Hellraiser III: Hell, on Earth
  • 1994 Red Sun Rising
  • 1998 Reasons of the Heart
  • 2000 Deep Core
  • 2000 Tripping the Rift
  • 2002 Psychic Murders

Television Career:
  • 1984 Paper Dolls
  • 1984 Spencer
  • 1985 The Cosby Show
  • 1986 Beverly Hills Madam
  • 1986 The Deliberate Stranger
  • 1986 The Twilight Zone
  • 1986 Family Ties
  • 1991 Mimi & Me
  • 1992 Quantum Leap
  • 1992 Grapevine
  • 1992 Red Dwarf
  • 1993 Danielle Steel's Star
  • 1993-1998 Star Trek: Deep Space Nine
  • 1998 Legion
  • 1998-2002 Becker
  • 2000 One True Love
  • 2002 Crossing the Line
  • 2002 Gleason
  • 2003 Code 11-14
  • 2017 Renegades