51 Anti-Aircraft Brigade was formed in August 1939 in Edinburgh, originally to command the Light Anti-Aircraft units of the 3 Anti-Aircraft Division, but later assumed responsibility for north east Scotland. 51 Anti-Aircraft Brigade later transferred to 12 AA Division and then 6 AA Group in 1942.
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.
| Aug 39 | Edinburgh |  | 3 Anti-Aircraft Division |
| Aug 42 | Edinburgh |  | 12 Anti-Aircraft Division |
| Oct 42 | Edinburgh |  | 6 Anti-Aircraft Group |
Order of Battle 1939
| 14 (West Lothian Royal Scots) Light Anti-Aircraft Regiment |
| 18 Light Anti-Aircraft Regiment |
| 19 Light Anti-Aircraft Regiment |
| 31 Light Anti-Aircraft Regiment |
| 32 Light Anti-Aircraft Regiment |
Order of Battle 1940-41
| 108 Heavy Anti-Aircraft Regiment |
| 40 Light Anti-Aircraft Regiment |
| 67 Light Anti-Aircraft Regiment |
Order of Battle 1942
| 65 (Manchester Regiment) Heavy Anti-Aircraft Regiment – Joined & left Dec 41 |
| 100 Heavy Anti-Aircraft Regiment – joined Jun 42 |
| 101 Heavy Anti-Aircraft Regiment – joined Jun 41, left Jun 42 |
| 108 Heavy Anti-Aircraft Regiment – left Nov 40 |
| 114 Heavy Anti-Aircraft Regiment – Joined May 42 |
| 40 Light Anti-Aircraft Regiment – Left May 42 |
| 67 Light Anti-Aircraft Regiment – Left Spring 42 |
| 95 Light Anti-Aircraft Regiment – Left Jun 42 |
| 131 Light Anti-Aircraft Regiment – joined Jun 42 |
