124 Heavy Anti-Aircraft Regiment RA (TA) was formed at Fareham in March 1941. It served in Anti-Aircraft Command in the UK for its entire war. The Regiment was considered a new War Formed unit in January 1947. 124 Heavy Anti-Aircraft Regiment RA (TA) was re-designated as 65 Heavy Anti-Aircraft Regiment RA in April 1947.
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.
| Mar 41 | Formed | Fareham, Hampshire, UK | |
| Mar 41 |  |
5 Anti-Aircraft Division, 35 Anti-Aircraft Brigade | UK |
| Oct 41 | |
5 Anti-Aircraft Division, 27 Anti-Aircraft Brigade | Portsmouth, Hampshire, UK |
| Jan 43 |  |
2 Anti-Aircraft Group, 37 Anti-Aircraft Brigade | UK |
| May 43 | |
1 Anti-Aircraft Group | UK |
| Sep 43 | |
2 Anti-Aircraft Group, 5 Anti-Aircraft Brigade | UK |
| Oct 43 | |
3 Anti-Aircraft Group | UK |
| Mar 44 | |
2 Anti-Aircraft Group, 102 Anti-Aircraft Brigade | UK |
| Mar 45 | |
2 Anti-Aircraft Group, 37 Anti-Aircraft Brigade | UK |
Batteries
| Mar 41 | 410, 412, 415 |
| Aug 41 | 219, 410, 412, 415 |
| Feb 45 | 219, 410, 412 |