Byrne was born in Brockton, Massachusetts, and trained for the stage at the Leland Powers Theatrical School in Boston. Later she appeared in plays with such actors of the day as Joan Davis and Donald Meek.
Mary Byrne wrote numerous short story for various American and British magazines including Modern Weekly, Charm and Home Weekly. Byrne published her novel Softly Softly in 1958, under the pen name Marie Byrne.
Byrne died in Itchenor, England in 1961