(written from a Production point of view)
Forsyth had previously been a regular on the soap opera Days of Our Lives from 1976 through 1980. She would go on to originate the role of Sophia Capwell on another soap opera, Santa Barbara, co-starring Dame Judith Anderson and Ray Walston, among others. However, she would soon abandon the role and would be replaced by Judith McConnell, who had previously guest-starred on Star Trek: The Original Series.
She has made guest appearances on a number of other television series, including Barbary Coast and T.J. Hooker, both starring William Shatner, and in the third season Kung Fu episode "A Small Beheading", also with Shatner. She also appeared on Mannix (including one episode with Michael Bell and Jay Robinson), CHiPs (with Michael Dorn and William Schallert), Fantasy Island (starring Ricardo Montalban), Dallas (with Susan Howard and Larry Cedar), Murder, She Wrote (with Jason Evers, Lawrence Pressman, Eugene Roche, and William Windom), and the final episode of NYPD Blue (with Gordon Clapp and Bill Smitrovich), among others.
Forsyth made her film debut in the 1965 Western Shenandoah, co-starring with TOS guest actors Glenn Corbett and Paul Fix. For her role in this film, Forsyth earned a Golden Globe nomination as Most Promising Newcomer - Female. She would go on to star or appear in such films as Texas Across the River (1966, with Michael Ansara, Andrew Prine, and George D. Wallace), One Little Indian (1973, with Morgan Woodward, Robert Pine, Andrew Prine, Paul Sorenson, and Richard Hale), Gray Lady Down (1978, with Stephen McHattie, Ronny Cox, and Robert Ito), Disclosure (1994, with Suzie Plakson, Jacqueline Kim, Jack Shearer and David Drew Gallagher playing her character's son, and John Carpenter's Ghosts of Mars (2000, with Joanna Cassidy). The majority of her movies, however, are those made for television, many of which feature fellow Star Trek alumni. These include 1970's The Brotherhood of the Bell (with Robert Pine and William Smithers), 1971's City Beneath the Sea (with James Darren and Whit Bissell), 1993's A Case for Murder (with Eugene Roche, Samantha Eggar, Thomas Kopache, Robert DoQui, and Bruce French), 1995's Abandoned and Deceived (with Bibi Besch, Gordon Clapp, Robert Hooks, and Patti Yasutake), and 2003's A Time to Remember (with Louise Fletcher).
Other Trek connections
- Is There a Doctor In the House? (1971 TV movie) with William Windom
- Powderkeg (1971 TV movie) with Michael Ansara and Roy Jenson
- The Death of Me Yet (1971 TV movie) with Meg Foster
- A Friendship in Vienna (1988 TV movie) with Stephen Macht and narrated by Jean Simmons
- Nashville Beat (1990 TV movie) with Richard Herd
- Exit to Eden (1994 feature film) with Iman and Stephanie Niznik