66 Light Anti-Aircraft Regiment RA (TA) was formed in December 1940 in Belfast, with two batteries from 102 Heavy Anti-Aircraft Regiment . The Regiment moved to Egypt in March 1943. It fought in Sicily and Italy before moving to Greece in October 1944. 66 Light Anti-Aircraft Regiment RA (TA) was disbanded April 1945 in the Middle East.
Illustrations of the formation badges under which a unit served or supported are given. This is no guarantee that the unit used this formations badge.
| Dec 40 | Formed from batteries from 102 Heavy Anti-Aircraft Regiment | Belfast, UK | |
| Dec 40 |  |
12 Anti-Aircraft Division, 3 Anti-Aircraft Brigade | Northern Ireland, UK |
| Jun 42 |  |
6 Anti-Aircraft Division, 71 Anti-Aircraft Brigade | East Kent, UK |
| Sep 42 |  |
War Office Reserve | UK |
| Mar 43 |  |
Middle East Forces | Port Tewfik, Egypt |
| Jul 43 |  |
8 Army, 2 Anti-Aircraft Brigade | Syracuse, Sicily |
| Jan 44 | |
8 Army, 73 Anti-Aircraft Brigade | Catania, Sicily |
| Feb 44 | |
8 Army, 62 Anti-Aircraft Brigade | Foggia, Italy |
| Apr 44 | |
8 Army, 52 Anti-Aircraft Brigade | Foggia, Italy |
| Sep 44 | Converted to a transport unit for Greece | ||
| Oct 44 | Arkforce | Piraeus, Greece | |
| Apr 45 | Disbanded |
Batteries
| Dec 40 | 175, 176 |
| Mar 41 | 175, 176, 251 |
| Sep 41 | 175, 176, 276 |
| Feb 42 | 175, 176, 276, 459 |
| Jul 42 | 175, 176, 276 |
Equipment
| Dec 40 | A few 3 inch guns, Lewis MG’s, Z Projectors (3 inch rockets) |
| Jan 41 | 12 x Bofors 40 mm Guns |
| Oct 41 | 38 x Bofors 40 mm Guns, 4 x 3 inch Naval Guns, 6 x Lewis MG’s |
| Oct 42 | 54 x Bofors 40 mm Guns |