Kathryn was born July 5, 1966 in Newton, Massachusetts (just outside of Boston). She and husband Terry Kinney have two children, daughter Maeve and son Carol Lincoln.
Erbe graduated from New York University's Tisch School of the Arts undergraduate drama program in 1990. She became a member of the Steppenwolf Theatre Company's ensemble in Chicago in 1993, which was co-founded by her husband.
Kathryn Erbe's Scores