Westminster St George's by-election, 1931

The Westminster St. George's by-election, 1931 was a parliamentary by-election held on 19 March 1931 for the British House of Commons constituency of Westminster St. George's.

The seat had become vacant on 14 February when the constituency's Conservative Member of Parliament (MP), Sir Laming Worthington-Evans, died aged 62. He had sat for the constituency since the 1929 general election, having previously been MP for Colchester since 1910; he had served in the cabinets of David Lloyd George and Stanley Baldwin during the 1920s.

The by-election took place during a campaign, led by the press magnates Lord Beaverbrook and Lord Rothermere, to remove Stanley Baldwin as Leader of the Opposition. The vehicles for their campaign were the United Empire Party and the Empire Free Trade Crusade.

The campaign had had some success. The Conservative Central Office had withdrawn support for its own candidate at the 1929 Twickenham by-election, who supported the Empire Free Trade policy. The UEP had won the 1930 Paddington South by-election from the Conservatives. The split in the right-wing vote between Conservative and UEP candidates at the Islington East by-election in February 1931 had allowed Labour to hold a seat they had been expected to lose.