Sandra Oh was born to Korean immigrant parents in the Ottawa suburb of Nepean, Ontario, where she attended Sir Robert Borden High School and founded the Environmental Club there. She became a ballet dancer and later became interested in acting while in high school, where she took drama classes, acted in school plays, and was a member of the drama club. Oh eventually studied drama at the National Theatre School in Montreal, whereafter she starred in a London, Ontario stage production of David Mamet's Oleanna.
Oh is known in Canada for her lead performances in the Canadian film Double Happiness, for which she won the Genie Award for Best Actress. Her other Canadian films include Long Life, Happiness and Prosperity, Wilby Wonderful, and Last Night, which she again won a Best Actress Genie for. Oh also won FIPA d'Or Best Actress at Cannes Film Festival for her role in The Diary of Evelyn Lau.
Oh is most familiar to American audiences from her roles in the popular films Under the Tuscan Sun and Sideways. On American television, she is renowned for her current role in the hit ABC medical series Grey's Anatomy, for which she has won both a 2006 Golden Globe Award for Best Supporting Actress in a Series and a 2005 Screen Actors Guild Award for Outstanding Performance by a Female Actor in a Drama Series. She had also made several guest appearances on the series Popular (1999) playing a humanities teacher.
In theatre, Oh has also starred in the world premieres of Jessica Hagedorn's Dogeaters at the La Jolla Playhouse and Diana Son's Stop Kiss at Joseph Papp's Public Theatre in New York.
In 2006, she will be featured in the film The Night Listener as "Anna," alongside Robin Williams and Toni Collette. Although Oh remains active in feature film, the critically acclaimed Grey's Anatomy remains her primary, current occupation.