Margaret Anna Cusack (6 May 1832 – 5 June 1899) was in order, an Irish Anglican nun, then a Roman Catholic nun and, later, a Religious Sister, as well as being the foundress of the Sisters of St. Joseph of Peace.
Emigrants Leave Ireland, engraving by Henry Doyle (1827–1893), from Mary Frances Cusack's Illustrated History of Ireland, 1868.
Margaret Anna Cusack was born in Coolock, County Dublin, Ireland into an aristocratic family and was raised in the Church of Ireland. When Cusack was a teenager her parents separated and she went to live with her grand-aunt in Exeter, Devon where she joined the Plymouth Brethren. At the age of 29 she was received into the Catholic Church and immediatey joined the Poor Clares in Newry, County Down.