Sister Carol Anne O'Marie, C.S.J., (August 28, 1933 – May 27, 2009) was a Roman Catholic sister in the Religious Congregation of the Sisters of St. Joseph of Carondelet. She was also a mystery writer. She wrote eleven novels, whose protagonist is Sister Mary Helen, an elderly sister who solves crimes. Most of the books are based in San Francisco, California, where O'Marie was born. Sister Carol Anne also ran a shelter for homeless women with Sister Maureen Lyons in Oakland, California. She died, aged 75, from Parkinson's disease on May 27, 2009.