Sillan was an early Irish saint and presbyter who served as the abbot of Bangor Abbey in County Down. As a disciple of the monastery's founder, Saint Comgall, he acted as either the second or third successor to the original leadership of the community. Historical records, including the Annals of Ulster and the Annals of Tigernach, document his life and death, with dates provided as either 608 or 610. His Irish name, Síoláin, is thought to mean a sieve or a seed-basket.