Saint Sillan (or Sillian) (Latin: Selanus; Irish: Síoláin) (died 608 or 610) was early Irish saint and abbot of Bangor Abbey, Bangor, County Down.

He was recorded as being a disciple and second or third successor of Saint Comgall, who was the founder and first abbot of the Benedictine monastery at Bangor.

[7] He is recorded in both the Annals of Tigernach and Annals of Ulster as abbot Bennchor (Bangor), in the former as Sillán moccu Cumaine, dying in 608 and the latter as Sillán moccu Minn, dying in 610.

[8][9] Moccu being the equivalent of the Latin gens, indicating an uncertain ancestry.

[10] Variations of his name include Siollan, Silvan, Sylvan, Sillian and Sillán, amongst others.