The 77th Searchlight Regiment (77th S/L Rgt) was an anti-aircraft (AA) unit of Britain's Royal Artillery (RA) formed during World War II.

[1][2][3] The Regimental Headquarters (RHQ) had been formed earlier, apparently with the intention of taking over the newly-raised 478–481 S/L Batteries, but these had been disposed elsewhere, 479 and 480 being disbanded and their personnel posted in July 1940 to help reform 1st S/L Rgt after the Dunkirk evacuation.

[5][6][7] At this period searchlights were deployed in clusters of three lights in an attempt to improve the chances of picking up enemy bombers and keeping them illuminated for engagement by AA guns or Royal Air Force (RAF) night-fighters.

Heavier raids against Swansea began on 4/5 January 1941, when a bomb put all the Gun Operations Room (GOR) telephone lines out of action.

The Luftwaffe returned to continue the 'Swansea Blitz' on the nights of 20/21 and 21/22 February, the city centre was devastated, and fires and delayed-action bombs destroyed communications.

[1][12][16][17][18] 93rd (Mixed) was the last searchlight regiment to be raised during the war, and afterwards a number of existing S/L units were converted to man Light Anti-Aircraft (LAA) guns, of which there was a great shortage.