LÉ Gráinne (CM10) was a Ton-class minesweeper in the Irish Naval Service.

She was named after Gráinne, a legendary princess who was promised to Fionn Mac Cumhail but ran away with his young follower Diarmuid.

Oulston was purchased from the Royal Navy in 1971, and commissioned as Gráinne.

She was stricken in 1987 and sold to Spanish interests for breaking.

This Ireland maritime–related article is a stub.