102nd Heavy Anti-Aircraft Regiment, Royal Artillery, was an air defence unit of Britain's Territorial Army (TA) formed at Antrim, Northern Ireland, during the period of international tension leading up to the outbreak of World War II. It defended Belfast and its shipyards during the early part of the war and then served in the Middle East. The regiment continued in the postwar TA until amalgamated in 1955.

The 3rd Anti-Aircraft Division was an air defence formation of the Territorial Army, part of the British Army, created in the period of tension before the outbreak of the Second World War. It defended Scotland and Northern Ireland during the early part of the war.