90 Light Anti-Aircraft Regiment RA was formed in November 1941 by conversion of 7th Battalion The South Wales Borderers, with three batteries. The Regiment moved to North Africa in March 1943. It took part in the operation at Pantelleria and went to Italy in December 1943. 90 Light Anti-Aircraft Regiment RA was disbanded in January 1945 .
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.
| Nov 41 | Formed from 7th Battalion South Wales Borderers | ||
| Nov 41 | Home Forces | UK | |
| Jan 42 |  |
1 Infantry Division | UK |
| Mar 43 | |
1 Infantry Division | Tunisia |
| Jun 43 | |
1 Infantry Division | Pantelleria |
| Jun 43 | |
1 Infantry Division | N Africa |
| Dec 43 | |
1 Infantry Division | Anzio, Italy |
| Nov 44 |  |
Allied Forces HQ | Italy |
| Jan 45 | Disbanded |
Batteries
| Nov 41 | 311, 312, 313 |