John Hamilton, 3rd Baron Hamilton of Dalzell

Baron Hamilton of Dalzell, in the County of Lanark, is a title in the Peerage of the United Kingdom. It was created in 1886 for the Liberal politician John Hamilton. He had previously represented Falkirk and Lanarkshire South in the House of Commons and after his elevation to the peerage served under William Ewart Gladstone as a Government Whip from 1892 to 1894. His eldest son, the second Baron, was a Government Whip from 1905 to 1911 in the Liberal administrations of Henry Campbell-Bannerman and H. H. Asquith and also served as Lord Lieutenant of Lanarkshire. His nephew, the third Baron, was Lord Lieutenant of Surrey. As of 2010^[update] the title is held by the latter's grandson, the fifth Baron, who succeeded his father in 2006.

The territorial designation is pronounced /diːɛl/ as in the usual pronunciation of the Scottish surname. The ancient family seat, Dalzell House in Motherwell, Lanarkshire, was sold in 1952. The third Baron lived at Beckington Castle in Somerset.