40 Anti-Aircraft Brigade was formed at Boston Lodge in South Ealing, London in September 1938. It served in Anti-Aircraft Command in the South and East of England for the entire war. Just before D Day it covered the invasion forces on the south coast. 40 Anti-Aircraft Brigade then became part of the Diver defences against the V1 rockets.
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.
| Sep 38 | Formed South Ealing, London
War station RAF Duxford |  | 2 Anti-Aircraft Division |
| Oct 42 | Nottinghamshire |  | 5 Anti-Aircraft Group |
| May 44 | Portsmouth | | 6 Anti-Aircraft Group |
| Jun 44 | South Coast Diver defences | | 6 Anti-Aircraft Group |
| Oct 44 | Thames Estuary Diver defences | | 1 Anti-Aircraft Group |
| Nov 44 | Thames Estuary Diver defences | | 9 Anti-Aircraft Group |
| Jan 45 | London | | 2 Anti-Aircraft Group |
Order of Battle September 1938
| 33 (St Pancras) Anti-Aircraft Battalion RE (332, 333, 334 Companies) – Searchlights |
| 36 (Middlesex) Anti-Aircraft Battalion RE (317, 345, 346, 424 Companies) – Searchlights |
| 56 (Middlesex) Anti-Aircraft Battalion RE (344, 425, 426 Companies) – Searchlights |
| 9th Battalion Middlesex Regiment (60 Searchlight Regiment) (429, 431, 439 Companies) |
| 10th (3rd City of London) Battalion Royal Fusiliers (69 Searchlight Regiment) (456, 457, 458 Companies) |
Order of Battle September 1940-41
| 78 (1st East Anglian) Heavy Anti-Aircraft Regiment (243, 244, 245, 409 Batteries) |
| 30 Light Anti-Aircraft Regiment (117, 118, 120 Batteries) |
| 36 (Middlesex) Searchlight Regiment (317, 345, 346, 424 Batteries) |
| 64 (Essex Regiment) Searchlight Regiment (441, 442, 443 Batteries) |
| 72 (Middlesex) Searchlight Regiment (465, 466, 467, 510 Batteries) |
Order of Battle September 1941-43
| 78 (1st East Anglian) Heavy Anti-Aircraft Regiment (243, 244, 245, 409 Batteries) – Left Summer 1941 |
| 30 Light Anti-Aircraft Regiment (117, 118, 120 Batteries) – Left December 1941 |
| 33 Light Anti-Aircraft Regiment (67, 68, 132 Batteries) – Joined Autumn left December 1941 |
| 96 Light Anti-Aircraft Regiment (80, 299, 300, 454, 479 Batteries) – Joined November 1941 left Spring 1942 |
| 138 Light Anti-Aircraft Regiment (80, 299, 300, 454, 479 Batteries) – Joined May 1942 left Summer 1943 |
| 36 (Middlesex) Searchlight Regiment (317, 345, 346, 424 Batteries) – Left September 1943 |
| 64 (Essex Regiment) Searchlight Regiment (441, 442, 443 Batteries) – Left June returned October 1942, left August 1943 |
| 72 (Middlesex) Searchlight Regiment (465, 466, 467, 510 Batteries) – Left late 1941 |
Order of Battle 1943-44
| 126 Heavy Anti-Aircraft Regiment (423, 425, 426, 431 Batteries) |
| 127 Heavy Anti-Aircraft Regiment (396, 411, 422, 433 Batteries) |
| 140 Heavy Anti-Aircraft Regiment (418, 420, 429, 430 Batteries) – Joined January 1944 |
| 129 Light Anti-Aircraft Regiment (425, 426, 427, 455 Batteries) |
| 134 Light Anti-Aircraft Regiment (192, 275, 287, 475 Batteries) |
| 135 Light Anti-Aircraft Regiment (445, 447, 450, 469 Batteries) |
Order of Battle Summer 1944
| 122 Heavy Anti-Aircraft Regiment (397, 400, 401 Batteries) – Joined September 1944 |
| 126 Heavy Anti-Aircraft Regiment (423, 425, 426, 431 Batteries) – Re-joined July 1944 |
| 127 Heavy Anti-Aircraft Regiment (396, 411, 422, 433 Batteries) – Left August 1944 |
| 132 (Mixed) Heavy Anti-Aircraft Regiment (435, 450, 457, 469 (M) Batteries) – Joined July left August 1944 |
| 134 (Mixed) Heavy Anti-Aircraft Regiment (459, 460, 461, 583 (M) Batteries) – Joined July left September 1944 |
| 136 Heavy Anti-Aircraft Regiment (182, 409, 432, 468 Batteries) – Joined July left August 1944 |
| 140 Heavy Anti-Aircraft Regiment (182, 409, 432, 468 Batteries) – Left July 1944 |
| 189 (Mixed) Heavy Anti-Aircraft Regiment (575, 577 (M) Batteries) – Joined August left September 1944 |
| 19 Light Anti-Aircraft Regiment (221, 263, 294 Batteries) – Joined August 1944 |
| 88 Light Anti-Aircraft Regiment (178, 289, 293 Batteries) – Joined August 1944 |
| 134 Light Anti-Aircraft Regiment (192, 275, 287, 475 Batteries) – Left July 1944 |
Order of Battle 1944-45
| 119 Heavy Anti-Aircraft Regiment (372, 377, 378 Batteries) – Joined October left November 1944 |
| 126 Heavy Anti-Aircraft Regiment (423, 425, 426, 431 Batteries) |
| 128 Heavy Anti-Aircraft Regiment (309, 431, 468 Batteries) – Joined March 1945 |
| 136 Heavy Anti-Aircraft Regiment (182, 409, 432, 468 Batteries) – Re-joined October 1944 |
| 150 (Mixed) Heavy Anti-Aircraft Regiment (456, 489, 515 (M) Batteries) – Joined November 1944 |
| 168 (Mixed) Heavy Anti-Aircraft Regiment (557, 559, 611 (M) Batteries) – Joined October left November 1944 |
| 19 Light Anti-Aircraft Regiment (221, 263, 294 Batteries) |
| 138 Light Anti-Aircraft Regiment (454, 458, 469 Batteries) – Joined October left December 1944 |
