Lionel Damer (16 September 1748 – 28 May 1807) was a British Whig politician.

Lionel Damer was the third son of Joseph Damer, 1st Earl of Dorchester by Lady Caroline Sackville (daughter of Lionel Cranfield Sackville, 1st Duke of Dorset and Elizabeth Colyear, his wife, daughter of Lieutenant-General Walter Philip Colyear (brother to David Colyear, 1st Earl of Portmore).

Lionel Damer was educated at Eton (1755–65) and Trinity College, Cambridge (1766).

They lived at Came House in Winterborne Came and there is a memorial to them in St Peter's Church nearby.

He held the seat until ill health forced him to retire shortly before the General Election in 1802.