Saint Fridolin, otherwise Fridolin of Säckingen is a legendary Irish missionary, apostle of the Alamanni and founder of Säckingen Abbey on the Upper Rhine. He is also the patron saint of the Swiss canton of Glarus.
His oldest Vita is dated to the 10th or 11th century.
Later tradition places the beginning of his mission during the reign of Clovis I, and his death during the reign of Theudebert I. The date of his death is traditionally given as 6 March in either 538 or 540.
Modern historiography has tended to place the founder of Säckingen Abbey in the 7th rather than 6th century, tentatively assuming the existence of a historical Saint Fridolin under Clovis II rather than Clovis I.