Joseph Damer, 1st Earl of Dorchester (12 March 1718 – 1798) was a wealthy landowner particularly associated with the reshaping of Milton Abbey and the creation of the village of Milton Abbas in Dorset, south-west England.
Born into a wealthy family (his great-uncle was a money-lender in Ireland), Damer was educated at Trinity College, Dublin in 1734–5, and became Member of Parliament (MP) for Weymouth in 1741 at the age of 21. He later represented Bramber in Sussex (1747) and Dorchester (1754). Damer was created Baron Milton of Shrone Hill, Tipperary, Ireland on 30 May 1753 and Baron Milton of Milton Abbey on 10 May 1762.
He married Lady Caroline Sackville, daughter of the 1st Duke of Dorset on 27 July 1742. Ten years later, he purchased Milton Abbey and embarked on an ambitious project to reshape the surrounding valley.
He replaced some existing buildings at the Abbey with a mansion house (designed initially by architect John Vardy, then by Sir William Chambers, and completed by James Wyatt) for his own use. Landscape gardener Capability Brown was commissioned to remodel the surrounding grounds.