Elizabeth Hirschboeck (March 10, 1903 – September 20, 1986), also known as Sister Mary Mercy, was a religious sister of the Maryknoll Sisters of St. Dominic and an international humanitarian.
On December 2, 1922, while a student at Marquette University, Hirschboeck survived a serious automobile accident. She was convinced that God spared her life so she could consecrate it more fully to him. She expressed her desire to join the Maryknoll Sisters at that time; however, Mother Mary Joseph encouraged her to first complete her medical studies.