Sophie Flack was born in Watertown, Massachusetts, and began her dance training at the age of seven at the Boston Ballet School with Carolyn Eaton. Ms. Flack continued her training with Jacqueline Cronsberg and Carter Alexander of Ballet Workshop of New England in Waltham, Massachusetts. After attending the 1998 Summer Program at the School of American Ballet (SAB), the official school of New York City Ballet, she was invited by SAB to continue her training during the Winter Program as a scholarship student. While at SAB, Ms. Flack performed in the School's lecture demonstrations with Suki Schorer and Jock Soto. She also studied at the Chautaqua Festival Dance summer program and Suzanne Farrell's Summer Workshop at the Kennedy Center. Ms. Flack became an apprentice with New York City Ballet in October 2000 and she joined the company as a member of the corps de ballet in October 2001.