Declán of Ardmore (, , died 5th century), also called
Déclán or
Declan, was an early
Irish saint of the
Déisi Muman, who was remembered for having converted the Déisi in the late 5th century and for having founded the monastery of
Ardmore (
Ard Mór) in what is now Co. Waterford. The principal source for his life and cult is a Latin
Life of the 12th century. Like
Ailbe of Emly,
Ciarán of Saigir and
Abbán of Moyarney, Declán is presented as a
Munster saint who preceded
Saint Patrick in bringing Christianity to Ireland. He was regarded as a patron saint of the
Déisi of East Munster.