Mary Anne Sadlier (31 December 1820—5 April 1903) was an Irish author. Sadlier published roughly twenty-three novels and numerous stories. She wrote for Irish immigrants in both the United States and Canada, encouraging them to attend mass and retain the Catholic faith. In so doing, Sadlier also addressed the related themes of anti-Catholicism, the Irish Famine, emigration, and domestic work. Her writings and translations are often found under the name Mrs. J. Sadlier. Earlier in her career, from 1840 to 1845, some of her works were published under the name "Anne Flinders".