St Cynidr was a 6th-century Catholic pre-congregational saint of South Wales and first Bishop of Glasbury, Powys.
Cynidr is buried in Glasbury, where he is venerated with a feast day of April 27.
The Parochial church of St Cynidr (St Kenider) at Glasbury commemorates his work although the current church was built c.1088AD. A holy well in the town is also attributed to him.
Cynidr was the son of St. Gwladys, grand son of King Brychan and the brother of St Eigon, the Patron Saint of Llanigon, near Glasbury.