Barbara Hershey (born Barbara Lynn Herzstein; February 5, 1948), once known as Barbara Seagull, is an American actress. In a career spanning over 50 years, she has played a variety of roles on television and in cinema in several genres, including Westerns and comedies. She began acting at age 17 in 1965, but did not achieve much critical acclaim until the latter half of the 1980s. By that time, the Chicago Tribune referred to her as "one of America's finest actresses."

Hershey won an Emmy and a Golden Globe for Outstanding Lead Actress in a Miniseries/TV Film for her role in A Killing in a Small Town (1990). She has also received Golden Globe nominations for Best Supporting Actress for her role as Mary Magdalene in The Last Temptation of Christ (1988) and for her role in Portrait of a Lady (1996). For the latter film, she was also nominated for an Academy Award for Best Supporting Actress and won the Los Angeles Film Critics Award for Best Supporting Actress. In addition, she has won two Best Actress awards at the Cannes Film Festival for her roles in Shy People (1987) and A World Apart (1988). She was also featured in Woody Allen's critically acclaimed Hannah and Her Sisters (1986), for which she was nominated for the British Academy Film Award for Best Supporting Actress and Garry Marshall's melodrama Beaches (1988), and she earned a second British Academy Film Award nomination for Darren Aronofsky's Black Swan (2010).

Establishing a reputation early in her career as a "hippie", Hershey experienced conflict between her personal life and her acting goals. Her career suffered a decline during a six-year relationship with actor David Carradine, with whom she had a child. She experimented with a change in stage name that she later regretted. During this time, her personal life was highly publicized and ridiculed. Her acting career was not well established until she separated from Carradine and changed her stage name back to Hershey. Later in her career, she began to keep her personal life private.