Clement Blair Peach (25 March 1946 – 23 April 1979) was a New Zealand-born teacher who was fatally assaulted by a police officer during an anti-racism demonstration in London, England.

A campaigner and activist against the far right, Peach was knocked unconscious in April 1979 during an Anti-Nazi League demonstration in Southall against a National Front (British National Front) election meeting in the town hall. He died the next day in hospital from head injuries that he sustained. Fourteen witnesses said they had seen members of the Metropolitan Police Special Patrol Group (SPG) strike Peach. No one was ever charged, but it was suspected that he been hit by a rubberised police radio. An inquest jury returned a verdict of death by misadventure in May 1980. Peachs girlfriend, Celia Stubbs, continued to campaign for many years for a public inquiry into his death. The Metropolitan Police Service reached an out-of-court settlement in 1989 with Peachs brother.

The Metropolitan Police reports into the death of Blair Peach were made available to the public on 27 April 2010.