The Battle of Cable Street was a series of clashes that took place at several locations in the East End of London, most notably Cable Street, on Sunday 4 October 1936. It was a clash between the Metropolitan Police, sent to protect a march by members of the British Union of Fascists led by Sir Oswald Mosley, and various anti-fascist demonstrators including local trade unionists, communists, anarchists, British Jews, and socialist groups. The anti-fascist counter-demonstration included both organised and unaffiliated participants.

The British Union of Fascists (BUF) was a British fascist political party formed in 1932 by Oswald Mosley. Mosley changed its name to the British Union of Fascists and National Socialists in 1936 and, in 1937, to the British Union. In 1939, following the start of the Second World War, the party was proscribed by the British government and in 1940 it was disbanded.