100 (The Gordon Highlanders) Anti-Tank Regiment RA (TA) was formed in November 1941 from 8th Battalion The Gordon Highlanders with four batteries at Buckie, Banff. It was re-designated 100 Light Anti-Aircraft/Anti-Tank Regiment in January 1944 and reverted to 100 (The Gordon Highlanders) Anti-Tank Regiment RA (TA) in the September. The Regiment disbanded in January 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.
| Nov 41 | Formed from 8th Battalion Gordon Highlanders | Buckie, Moray, UK | |
| Nov 41 | Home Forces | UK | |
| Jan 42 |  |
76 Infantry Division | UK |
| Nov 42 | Home Forces | UK | |
| Mar 43 |  |
2 Infantry Division | India |
| Jan 44 | Became 100 Light Anti-Aircraft/Anti-Tank Regiment 2 batteries to 122 Light Anti-Aircraft/Anti-Tank Regiment |
||
| Sep 44 | Became 100 Anti-Tank Regiment | ||
| Oct 44 | |
2 Infantry Division | Burma (Myanmar) |
| Apr 45 | |
2 Infantry Division | India |
Batteries
| Nov 41 | A, B, C, D |
| Mar 42 | Q, R, S, T |
| Jun 42 | Q, S, T |
| Jan 43 | 168, 169, 170 |
| Jun 43 | 168, 169, 170, 321 |
| Sep 44 | 169, 170, X, 401 |