William David Murray, 4th Earl of Mansfield and Mansfield KT DL (21 February 1806 – 1 August 1898), was a British Conservative politician.
The son of David William Murray, 3rd Earl of Mansfield and Frederica, daughter of Archbishop Markham, he succeeded his father in 1840 to the Earl of Mansfield (1792 creation), and grandmother, Louisa Murray, 2nd Countess of Mansfield, in 1843 as Earl of Mansfield (1776 creation). In 1829 he married Louisa, daughter of Cuthbert Eddison, Hebburn Hall, Durham, and they had one daughter and one son.
Murray was Tory Member of Parliament for Aldborough in 1830; for Woodstock in 1831; for Norwich from 1832–1837, and for Perthshire from 1837–1840. He served as a Lord of the Treasury in Sir Robert Peel's Administration from 1834–1835.
Murray was appointed Lord High Commissioner to the General Assembly of the Church of Scotland in 1852, 1858 and 1859. He was Lieutenant-Colonel of the Stirlingshire Militia from 1828–1855, Lord Lieutenant of Clackmannanshire from 1852, hereditary keeper of Scone Palace, and Senior Member of the Carlton Club. He was appointed a Knight of the Thistle in 1843 and was for a time Senior Knight.
He was succeeded by his grandson, Lord Balvaird.