131st Heavy Anti-Aircraft Regiment was an air defence unit of Britain's Royal Artillery formed during World War II. It was organised as the first 'Mixed' regiment in which women of the Auxiliary Territorial Service were integrated into the unit's personnel, though it later reverted to an all-male organisation. It defended the United Kingdom against aerial attack for two years.

35th Anti-Aircraft Brigade was an air defence formation of Anti-Aircraft Command in the British Territorial Army (TA) formed shortly before the outbreak of the Second World War. It defended the important naval base of Portsmouth during The Blitz.