Clement Blair Peach (25 March 1946 – 24 April 1979) was a New Zealand teacher who was killed during an anti-racism demonstration in Southall, London, England. A campaigner and activist against the far right, in April 1979 Peach took part in an Anti-Nazi League demonstration in Southall against a National Front election meeting in the town hall and was hit on the head, probably by a member of the Special Patrol Group (SPG), a specialist unit within the Metropolitan Police Service. He died in hospital that night.
An investigation by Commander John Cass of the Metropolitan Police's Complaints Investigation Bureau concluded that Peach had been killed by one of six SPG officers, and others had preserved their silence to obstruct his investigation. The report was not released to the public, but was available to John Burton, the coroner who conducted the inquest; excerpts from a leaked copy were also published in The Leveller and The Sunday Times in early 1980. In May 1980 the jury in the inquest arrived at a verdict of death by misadventure, although press and some pressure groups—notably the National Council for Civil Liberties—expressed concern that no clear answers had been provided, and at the way Burton conducted the inquest.
Celia Stubbs, Peach's partner, campaigned for the Cass report to be released and for a full public inquiry. An inquiry was rejected, but in 1989 the Metropolitan Police paid £75,000 compensation to Peach's family. In 2009 Ian Tomlinson died after he was struck from behind by a member of the Territorial Support Group, the SPG's successor organisation; the parallels in the deaths proved to be the catalyst in the release of the Cass report to the public. The Metropolitan Police commissioner, Sir Paul Stephenson, released the report and supporting documentation. He also offered an official apology to Peach's family.
The policing of the demonstration in Southall damaged community relations in the area. Since Peach's death the Metropolitan Police have been involved in a series of incidents and poorly conducted investigations—the 1993 murder of Stephen Lawrence, the death of Jean Charles de Menezes in 2005, the botched 2006 Forest Gate raid and the death of Tomlinson—all of which tarnished the image of the service. Peach's death has been remembered in the music of The Pop Group, Ralph McTell and Linton Kwesi Johnson; the National Union of Teachers set up the Blair Peach Award for work for equality and diversity issues and a school in Southall is named after him.