Steel-Maitland served under David Lloyd George as Under-Secretary of State for the Colonies from 1915 to 1917. The latter year he was created a Baronet, of Sauchie in the County of Stirling. He then held office under Lloyd George as Secretary for Overseas Trade in his capacity as Head of the Department of Overseas Trade (Development and Intelligence) from 1917 to 1919. In 1924 he was sworn of the Privy Council and appointed Minister of Labour under Stanley Baldwin, with a seat in the cabinet, a post he retained until the government fell in June 1929.