The 40th Light Anti-Aircraft Regiment, Royal Artillery, (40th LAA Rgt) was a Scottish air defence unit of Britain's Territorial Army (TA) during World War II. After serving with Anti-Aircraft Command in the defence of the UK, it joined 51st (Highland) Infantry Division and served with it at Alamein, in Tunisia and Sicily. It landed in Normandy on D + 1 and fought through the campaign in North West Europe, including the crossing of the Rhine, until VE Day. The regiment was reformed in the postwar TA but was amalgamated with other Scottish anti-aircraft units in 1950.