Colonel Sir William Henry Houghton Gastrell CMG TD FRGS (24 September 1852 – 11 April 1935) was Conservative MP for Lambeth North. He was born in Gloucestershire and educated at Cheltenham College. He moved to London where he obtained a commission in the Middlesex Yeomanry, rising to the rank of major and second in command of the unit in 1901. In 1909 he was awarded the Territorial Decoration. He was subsequently promoted to the rank of colonel in the Army Service Corps commanding Woolwich District. He was knighted in 1917.