Elli was a religious leader and theologian active in 6th-century Wales. While traditions regarding the saint's gender vary, historical accounts link this figure to the lineage of King Brychan. As the foster child of Saint Cadoc, Elli received an education at the Llancarfan settlement before eventually succeeding Cadoc as Abbot. The saint is closely associated with several locations across Carmarthenshire and Monmouthshire, most notably through the founding of a church near the River Lliedi.