Lydia Sellon was a 19th-century Anglican nun who established several religious institutions. Born in Hampstead in 1821, she responded to a call for social and educational assistance in Devonport. Through her leadership, she formed the Devonport Sisters of Mercy, which later merged with the Sisterhood of the Holy Cross to become the Society of the Most Holy Trinity. Her work included managing orphanages, industrial schools, and providing nursing care during cholera outbreaks. She eventually moved to West Malvern, where she died in 1876.