Margolin was born in the summer of 1943 in New York City, the daughter of a Russian accountant. She studied at the School of Performing Arts. In 1961 (at age 18) she won during the New York Shakespeare Festival an important role in a film adaptation of a novel by Morris West, Daughters of Silence. This made her acting talent as it were discovered.
In 1962, she played her first role, as female lead in the film David and Lisa. She played the love of the main character in the movie Enter Laughing (1967). In the film Take the Money and Run (1969) she played the love of the bumbling thief played by Woody Allen, and in Annie Hall (1977) she played a social-growing woman of the character of Woody Allen.
Margolin died of ovarian cancer at the age of 50 on december 17, 1993 in Los Angeles. She was cremated and her ashes were placed in a urntuin in the Westwood Memorial Park, where the ashes of many well-known persons is.
Margolin is sometimes identified as the sister of actor Stuart Margolin and his brother, Director Arnold Margolin. However, obituaries of Margolin and her father have indicated that they had no brothers.
- David and Lisa (1962)
- Morituri (1965)
- The Greatest Story Ever Told (1965)
- Bus Riley's Back in Town (1965)
- Nevada Smith (1966)
- El ojo que espía (1966)
- Enter Laughing (1967)
- Buona Sera, Mrs. Campbell (1968)
- Take the Money and Run (1969)
- Pray for the Wildcats (1973)
- Planet Earth (1974)
- Annie Hall (1977)
- Last Embrace (1979)
- Ghostbusters II (1989)