Tricia O'Neil (born Patricia Lou O'Neil; March 11, 1945) is an American actress from Shreveport, Louisiana. She is known for her diverse roles in film and television spanning decades. O'Neil made her film debut in 1972 in "The Legend of Nigger Charley" and appeared in films such as "The Gumball Rally" (1976), "Piranha II: The Spawning" (1982), and "Titanic" (1997). She has made numerous guest appearances on TV shows like "Columbo," "Murder, She Wrote," "Star Trek: The Next Generation," where she notably played Captain Rachel Garrett—the first female captain of the U.S.S. Enterprise— "Star Trek: Deep Space Nine," "Babylon 5," and many others.

O'Neil began her performing career as a jazz, blues, and folk singer before transitioning to acting. She studied at Baylor University and made her professional theatrical debut on Broadway in the musical "Two by Two." Her acting career is distinguished by versatility, including roles in science fiction and drama. She retired from screen acting in 2001.