- Started dance classes at age 4 and began singing at age 10, winning the lead in a community-theater production of Annie.
- Has a brother, actor Hunter Foster, with an extensive theater career similar to her own. They've performed together on Broadway twice, in Grease in 1996 and Les Misérables in 2000.
- Before Thoroughly Modern Millie went to Broadway, she was selected from the chorus to replace the lead actress. She went on to win the 2002 Tony for Best Actress in a Musical for the role.
- Recorded the solo CDs Wish (2009) and An Evening With Sutton Foster—Live at the Café Carlyle (2011).
- Has held dance workshops at Ball State University in Muncie, IN. In 2012, she codirected a play at the university and received an honorary doctorate from them.
- Enjoys drawing, painting and crocheting, and sells some of her artwork online.