Denise Michelle Crosby (born November 24, 1957) is an American actress best known for portraying Security Chief Tasha Yar on Star Trek: The Next Generation. She is also known for her numerous film and television roles, for starring in and producing the film Trekkies. She is the granddaughter of the late entertainer Bing Crosby.

Crosby was born in Hollywood, California, the daughter of Marilyn Scott and actor Dennis Crosby. Her paternal grandfather was actor/singer/comedian Bing Crosby. She attended LeConte Junior High School with actress Rita Wilson (wife of Tom Hanks). Her choice of career solidified at an early age and was influenced by the involvement of other family members in show business.

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, and as a sheriff on The Adventures of Brisco County, Jr. episode "No Man's Land". In the early 1990s, she played the role of the mayor in the short-lived series Key West. She also appeared in two episodes of the cable television series Red Shoe Diaries, playing a different character in each episode. 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. In 1991, she was a guest star in a first season The Flash episode as Dr. Rebecca Frost. In 2006, 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.