Mary McCormack began her acting career performing in Gian Carlo Menotti's Christmas opera, "Amahl and the Night Visitors". "I was twelve but looked like an eight-year-old boy" she recalls. "As luck would have it, none of the boys in town could sing, so I got the part and wore a hat". Mary continued working regionally throughout New Jersey and continued her education at Trinity College in Hartford, Connecticut. At Trinity, she majored in English and painting and continued her stage work in many more musicals. Mary finished an acting program at the William Esper Studio. She has worked in many New York theaters, some of which include The Atlantic Theatre Company, Alice's 4th Floor and Naked Angels, where she recently appeared in Jon Robin Baitz's "A Fair Country".
Graduated from the Wardlaw-Hartridge School in Edison, New Jersey in 1987. Daughter, Margaret Morris, was born on 3rd September 2004 Sister of actor Will McCormack.