Landévennec Abbey (Abbaye de Landévennec) was a monastery in Brittany, now in Finistère, France. It existed from its foundation at Landévennec, traditionally by Winwaloe in the late fifth century, to 1793, when the monastery was abandoned and sold. In 1950 it was bought and rebuilt by the Benedictines of Kerbénéat.

It became a Benedictine foundation in the eighth century. It was attacked and burned by Vikings in 913; it was subsequently rebuilt in stone.