Frederick William Lambton, 4th Earl of Durham (19 June 1855 – 31 January 1929) was a British peer, a Liberal (and later Liberal Unionist) politician, and the son of George Lambton, 2nd Earl of Durham. He inherited the Earldom from his twin brother, John Lambton, 3rd Earl of Durham, when the latter died with no legitimate children. He married Beatrix Bulteel (1859 – 27 April 1937), his second cousin once removed, on 26 May 1879). They had six children: