Rossum was born in New York City in 1986 and attended the Spence School until 1996, when she began to homeschool through private tuition and by enrolling in programs offered by Stanford University’s Education Program for Gifted Youth (EPGY) and Northwestern University’s Center for Talent Development (CTD).

Emmy Rossum started her carrier as a singing at the Metropolitan Opera when she was 6 years old. She was trained there in stagecraft and classical vocal technique in order to sing the children’s parts in the company’s regular performances. During the next five years, Rossum appeared in 20 different operas, singing in five languages.

In 1996, she sang in Franco Zeffirelli’s new production of “Carmen” and in Tim Albery’s production of Benjamin Britten’s “A Midsummer Night’s Dream.”

Emmy Rossum made her theatrical feature debut in the indie Songcatcher in the year of 2000 which won the Special Jury Award for Outstanding Ensemble Performance at the Sundance Film Festival in January, 2000. Rossum received an Independent Spirit Award nomination in the category of Best Debut Performance for her performance as an Appalachian orphan.

Rossum made her television debut at the age of eleven as a recurring character on the long running American daytime program “As the World Turns.” She then guest-starred on the award-winning series Law and Order and The Practice.