Born Angela Maxine O'Brien on January 15, 1937 in San Diego, California. Her film debut was a one-minute scene in MGM's Babes on Broadway (1941). Her big moment came when she was cast in Journey for Margaret (1942). This film shot her into instant stardom and also resulted in Angela changing her name to Margaret. Throughout the 1940s Margaret was a major child star. Her unforgettable performance as "Tootie" in Vincente Minnelli's Meet Me in St. Louis (1944) won her an Academy Award as "Outstanding Child Actress" of her day. The Oscar was stolen and she was unable to regain it for nearly fifty years until two memorabilia collectors came across it at a swap meet and managed to give it back to her.

She gave brilliant performances in such films as The Canterville Ghost (1944), Our Vines Have Tender Grapes (1945), The Secret Garden (1949) and Little Women (1949). By the early 1950s Margaret had made a mint for MGM and also earned a personal fortune. But like most other child stars, she failed in her bid to graduate into adolescent roles and in 1951 she retired from the screen. She remained active on TV and on the dinner-theater circuit. In 1979 she began a stint as a civilian aide for Southern California to Secretary of the Army Clifford Alexander.

Margaret O'Brien's unforgettable performance as "Tootie" in Vincente Minnelli's Meet Me in St. Louis (1944) won her an Academy Award as "Outstanding Child Actress" of her day.

1941 Babes on Broadway – Maxine, Little Girl at Audition (uncredited)

1942 Journey for Margaret – Margaret

1943 You, John Jones! (Short) – Daughter

1943 Dr. Gillespie’s Criminal Case – Margaret

1943 Thousands Cheer – Customer in Red Skelton Skit

1943 Madame Curie – Irene Curie – Age 5

1943 Lost Angel – Alpha

1943 Jane Eyre – Adele Varen

1944 Meet Me in St. Louis – Tootie

1944 The Canterville Ghost – Lady Jessica de Canterville

1944 Music for Millions – ‘Mike’

1945 Our Vines Have Tender Grapes – Selma Jacobson

1946 Bad Bascomb – Emmy

1946 Three Wise Fools – Sheila O’Monahan

1947 The Unfinished Dance – ‘Meg’ Merton

1948 Tenth Avenue Angel – Flavia Mills

1948 Big City – Midge

Margaret O'Brien plays Beth in this 1949 adaptation of the classic book. Beth's only earthly love is music. She adores playing the piano and singing, and the only material thing that she wants is a nicer piano, since her family's is old and out of tune. Beth has a significant effect on the people around her, especially her sister, Jo although she dies as she reaches adulthood. Margaret is only 12 in this role.

1949 Little Women – Beth

1949 The Secret Garden – Mary Lennox

1951 Her First Romance – Betty Foster

1952 Girls Hand in Hand – Catherine McDermott

1956 Glory – Clarabel Tilbee

1968 Annabelle Lee

1974 Death in Space (TV Movie)

1981 Amy – Hazel Johnson

1996 Sunset After Dark

2002 Dead Season (Video) – Friendly Looking Lady

2009 Elf Sparkle Meets Christmas the Horse (TV Movie) – Miss Coyote (voice)

2009 Dead in Love – Cris

2010 Frankenstein Rising

2010 Elf Sparkle and the Special Red Dress (TV Movie) – Mrs. Claus

2014 Dr. Jekyll and Mr. Hyde (pre-production) – Ms. Stevenson

2013 Classic Film Hall of Fame: Awarded May 12, 2013 at the Rheem Theatre in Moraga, California

1990 Young Artist Awards Former Child Star Lifetime Achievement Award

1960 Walk of Fame – Motion Picture on 8 February at 6606 Hollywood Blvd.

1960 Walk of Fame – Television on 8 February at 1634 Vine Street.

1945 Oscar Outstanding Child Actress - Winner