Denise Michelle Crosby is an American actress best known for portraying Security Chief Tasha Yar in Season One of Star Trek: The Next Generation as well as Yar’s own daughter, the half-Romulan Commander Sela, in subsequent seasons. She is also known for her numerous film and television roles and for starring in and producing the film Trekkies. Crosby was cast in the role of Tasha Yar. She had originally been chosen to play Counsellor Deanna Troi before Gene Roddenberry switched the roles that she and Marina Sirtis had initially been given.

Crosby’s first high-profile role was as Lisa Davis on the soap opera Days of Our Lives. She has appeared as Dr. Gretchen Kelly in three episodes of Lois & Clark: The New Adventures of Superman. Crosby had a small recurring role in Aaron Spelling’s prime-time drama, Models Inc., a spin-off from Melrose Place. She was a guest star on the eighth season of The X-Files for two episodes, in which she plays a doctor who took examinations of Agent Scully’s baby.

She was a guest star in Dexter as Dexter’s first victim. Crosby had a recurring role in Southland as Detective Dan “Sal” Salinger’s wife. One of her very first film appearances was in the Nick Nolte/Eddie Murphy film 48 Hrs. She appeared in Stephen King’s Pet Sematary and Quentin Tarantino’s Jackie Brown. She also appeared in the movie Deep Impact starring Elijah Wood. Crosby has a recurring role on Showtime’s series Ray Donovan.