The 1940 Mitcham by-election was held on 19 August 1940. The by-election was held due to the death of the incumbent Conservative MP, Richard Meller. It was won by the Conservative candidate Malcolm Robertson,^[1] who was unopposed as during the Second World War the political parties in the Coalition Government had agreed not to contest by-elections when a vacancy arose in any of the seats held by the other coalition parties.^{[citation needed]}