William Dacre, 7th Baron Greystock, later 3rd Baron Dacre of Gilsland (ca. 1493 - 18 November 1563) was an English peer, a Cumberland landowner, and the holder of important offices under the Crown, including many years' service as Warden of the West Marches.
The son of Thomas Dacre, 2nd Baron Dacre, by his marriage to Elizabeth Greystoke, Dacre succeeded his mother as Baron Greystock on 14 August 1516 and his father as Baron Dacre in 1525. From his father, he inherited about 70,000 acres (280 km²) of land in Cumberland, 30,000 acres (120 km²) in Yorkshire and 20,000 acres (80 km²) in Northumberland.
On an unknown date between 18 May 1519 and 1527, he married Lady Elizabeth Talbot, the fifth daughter of George Talbot, 4th Earl of Shrewsbury, by his marriage to Anne Hastings, only daughter of William Hastings, 1st Baron Hastings. She was still alive on 6 May 1552.
He was Captain of Norham Castle in 1522-23, Steward of Penrith, Warden of the West Marches from 1527 to 1534 and again from 1549 until his death in 1563, Governor of Carlisle 1549 to 1551 and Warden of the Middle Marches from 1553 until 1555.
Children of William Dacre and Elizabeth Talbot: