Harry Louis Nathan, 1st Baron Nathan, PC (2 February 1889 – 23 October 1963) was a Liberal politician, who later joined the Labour Party.
Nathan was born in London in 1889, son of Michael Henry Nathan, a fine art publisher and Justice of the peace. Educated at St Paul's School, he became a solicitor and member of the firm of Herbert Oppenheimer Nathan and Vandyk. He became honorary secretary of the Brady Working Lads' Club, the oldest and largest of the London Jewish Lads' Clubs.
Nathan served in World War I, leaving with the rank of Major. He acted as honorary solicitor to the Land and Nation League.
He stood as a Liberal without success in the 1924 general election for Whitechapel and St. George's. He was first elected in 1929 as Member of Parliament (MP) for Bethnal Green North East and was re-elected in 1931. In 1934, he defected to the Labour Party. Although Labour won the seat at the 1935 general election, Nathan was not their candidate, opting instead to stand in Cardiff South. He lost by just 541 votes.
In 1937, Nathan was able to return to Parliament in a by-election in Wandsworth Central as the Labour candidate. He in turn stepped down in 1940 to make way for Ernest Bevin, and was created a hereditary peer as Baron Nathan of Churt in the County of Surrey on 28 June 1940. He continued in active politics from the House of Lords, serving as Under-Secretary of State for War (1945–46 and Minister for Civil Aviation (4 October 1946 - 31 May 1948). He was made a Privy Counsellor in 1946.