The division was formed on 1 November 1940 by splitting 5 Anti-Aircraft Division, with the new formation taking responsibility for the City of Bristol and the counties of Somerset, Dorset, Devon and Cornwall. This area included the Bristol Aeroplane Company factory and airfield at Filton, and the Royal Navy dockyards at Devonport (Plymouth) and Portland.
On re-organisation of Anti-Aircraft Command in October 1942, 8 Anti-Aircraft Division merged with 5 Anti-Aircraft Division into 3 Anti-Aircraft Group based at Bristol
HQ Bristol
Order of Battle 1939-40
| 46 Anti-Aircraft Brigade – Bristol |
| 76 (Gloucestershire) Heavy Anti-Aircraft Regiment |
| 23 Light Anti-Aircraft Regiment – to 5 Anti-Aircraft Division by May 41 |
| 66 (Gloucestershire Regiment) Searchlight Regiment (part) |
| 68 (Monmouthshire Regiment) Searchlight Regiment |
| 55 Anti-Aircraft Brigade – Plymouth and Falmouth, Cornwall |
| 56 (Cornwall) Heavy Anti-Aircraft Regiment |
| 118 Heavy Anti-Aircraft Regiment (part) – new regiment raised in Dec 40; to 9 Anti-Aircraft Division by May 41 |
| 58 (Argyll and Sutherland Highlanders) Light Anti-Aircraft Regiment – part deployed at Plymouth, part under 65 Anti-Aircraft Brigade at Southampton; left to join 11 Support Group in May 41 |
| 81 Searchlight Regiment – new unit formed in Nov 40 from existing Searchlight Battery of Cornwall Fortress Royal Engineers |
| 82 Searchlight Regiment – new unit formed in Nov 40 from existing Searchlight Battery of Dorset Fortress Royal Engineers |
| 60 Anti-Aircraft Brigade – Exeter, Yeovil and Portland |
| 104 Heavy Anti-Aircraft Regiment |
| 44 Light Anti-Aircraft Regiment |
| 66 Searchlight Regiment (part) |
| 64 Anti-Aircraft Brigade – Airfield sector layout |
| 35 Light Anti-Aircraft Regiment |
| 2 Searchlight Regiment |
| 3 (Ulster) Searchlight Regiment – converted into 4 (Ulster) Light Anti-Aircraft Regiment in Jan 42 |
| 76 Searchlight Regiment |
| 85 Searchlight Regiment – new unit raised in Jan 41 |
| Divisional unit |
| 9 Anti-Aircraft Z Regiment – formed by 8 Anti-Aircraft Division in Jan 41 |
Order of Battle 1941-42
| 46 Anti-Aircraft Brigade |
| 59 (Essex Regiment) Heavy Anti-Aircraft Regiment – from 6 Anti-Aircraft Division Dec 41; to War Office control as part of the field force Mar 42; later to Operation Torch |
| 76 (Gloucestershire) Heavy Anti-Aircraft Regiment – to the 69 Anti-Aircraft Brigade by Dec 41 |
| 104 Heavy Anti-Aircraft Regiment – to 5 Anti-Aircraft Division in Dec 41 |
| 112 Heavy Anti-Aircraft Regiment – from 11 Anti-Aircraft Division by May 41; to 9 Anti-Aircraft Division by Dec 41 |
| 116 Heavy Anti-Aircraft Regiment – new unit formed in Nov 40; to 55 Anti-Aircraft Brigade by Dec 41 |
| 119 Heavy Anti-Aircraft Regiment – from 1 Anti-Aircraft Division by May 41; to 64 Anti-Aircraft Brigade by Dec 41 |
| 133 (Mixed) Heavy Anti-Aircraft Regiment – new unit formed Sep 41 |
| 140 Heavy Anti-Aircraft Regiment – new unit formed Dec 41; to 69 Anti-Aircraft Brigade by May 42 |
| 150 (Mixed) Heavy Anti-Aircraft Regiment – new unit formed Feb 42 |
| 165 Heavy Anti-Aircraft Regiment – new unit formed Jul 42 |
| 36 Light Anti-Aircraft Regiment – from 1 Anti-Aircraft Division by May 41; to 69 Anti-Aircraft Brigade Summer 41 |
| 47 Light Anti-Aircraft Regiment – from 69 Anti-Aircraft Brigade by Dec 41; to Operation Torch 1942 |
| 133 Light Anti-Aircraft Regiment – from 69 Anti-Aircraft Brigade Jul 42 |
| 66 Searchlight Regiment – to 69 Anti-Aircraft Brigade Summer 41 |
| 68 Searchlight Regiment – to 69 Anti-Aircraft Brigade Summer 41 |
| 1 Anti-Aircraft Z Regiment – from 1 Anti-Aircraft Division by May 41, returned by Dec 41 |
| 55 Anti-Aircraft Brigade |
| 56 Heavy Anti-Aircraft Regiment– left for India in Dec 41 |
| 79 (Hertfordshire Yeomanry) Heavy Anti-Aircraft Regiment – from 11 Anti-Aircraft Brigade for Jul 42 |
| 103 Heavy Anti-Aircraft Regiment – from 4 Anti-Aircraft Division May 42 |
| 116 Heavy Anti-Aircraft Regiment – from 46 Anti-Aircraft Brigade by Dec 41 |
| 162 (Mixed) Heavy Anti-Aircraft Regiment – new unit formed Jun 42 |
| 166 (Mixed) Heavy Anti-Aircraft Regiment – new unit formed Aug 42 |
| 36 Light Anti-Aircraft Regiment – from 69 Anti-Aircraft Brigade by Dec 41; left for India in Apr 42 |
| 44 Light Anti-Aircraft Regiment – from 9 Anti-Aircraft Division Jan 42 (previously 60 Anti-Aircraft Brigade ); left for India in Mar 42 |
| 46 Light Anti-Aircraft Regiment – from 9 Anti-Aircraft Division by May 41 |
| 55 (Devonshire) Light Anti-Aircraft Regiment – from War Office Reserve in Apr 42; later to Ceylon |
| 137 Light Anti-Aircraft Regiment – new unit formed Feb 42 |
| 29 (Kent) Searchlight Regiment– from 6 Anti-Aircraft Division Jan 42; to 60 Anti-Aircraft Brigade Jun 42 |
| 81 Searchlight Regiment – converted into unbrigaded 131 Light Anti-Aircraft Regiment in Mar 42 |
| 82 Searchlight Regiment – to 64 Anti-Aircraft Brigade Dec 41 |
| 85 Searchlight Regiment – from 64 Anti-Aircraft Brigade by Dec 41; converted into 132 Light Anti-Aircraft Regiment in 5 Anti-Aircraft Division in Mar 42 |
| 9 Anti-Aircraft Z Regiment – from 60 Anti-Aircraft Brigade by Dec 41 |
| 60 Anti-Aircraft Brigade |
| 108 Heavy Anti-Aircraft Regiment – from Orkney and Shetland Defences (OSDEF) by Sept 42 |
| 12 (Finsbury Rifles) Light Anti-Aircraft Regiment – from 1 Anti-Aircraft Division by May 41; left Anti-Aircraft Command and joined War Office Reserve Jun 41, later to Persia and Iraq Command (PAIFORCE) |
| 44 Light Anti-Aircraft Regiment – to 9 Anti-Aircraft Division by Dec 41; then to 55 Anti-Aircraft Brigade Jan 42 |
| 67 Light Anti-Aircraft Regiment – from 3 Anti-Aircraft Division by Sept 42 |
| 29 (Kent) Searchlight Regiment – from 55 Anti-Aircraft Brigade Jun 42 |
| 74 (Essex Fortress) Searchlight Regiment – from 6 Anti-Aircraft Division Jan 42 |
| 76 Searchlight Regiment – from 64 Anti-Aircraft Brigade Dec 41; to 69 Anti-Aircraft Brigade Aug 42 |
| 88 Searchlight Regiment – new unit formed in Mar 41 |
| 89 Searchlight Regiment – new unit formed in Mar 41; converted into 133 Light Anti-Aircraft Regiment Mar 42; to 69 Anti-Aircraft Brigade June 42 |
| 9 Anti-Aircraft Z Regiment – to 55 Anti-Aircraft Brigade by Dec 41 |
| 64 Anti-Aircraft Brigade – Left August 1942 |
| 98 Heavy Anti-Aircraft Regiment – from 4 Anti-Aircraft Division May 42 |
| 119 Heavy Anti-Aircraft Regiment – from 46 Anti-Aircraft Brigade by Dec 41; to 9 Anti-Aircraft Division Jun 42 |
| 35 Light Anti-Aircraft Regiment – left in Nov 41 for Singapore, where it was captured in Feb 42 |
| 75 (Middlesex) Light Anti-Aircraft Regiment – joined from unbrigaded by Dec 41; left in Jul 42, later in invasion of Sicily (Operation Husky) |
| 87 Light Anti-Aircraft Regiment – new unit formed Oct 41; to 9 Anti-Aircraft Division Jun 42 |
| 127 (Queens) Light Anti-Aircraft Regiment– converted from 63rd (Queens) Searchlight Regiment, joined Jul 42 |
| 2 Searchlight Regiment |
| 3 Searchlight Regiment – to 69 Anti-Aircraft Brigade Dec 41 |
| 76 Searchlight Regiment – to 60 Anti-Aircraft Brigade Dec 41 |
| 82 Searchlight Regiment – from 55 Anti-Aircraft Brigade Dec 41 |
| 85 Searchlight Regiment – to 55 Anti-Aircraft Brigade by Dec 41 |
| 69 Anti-Aircraft Brigade – new formation joined June 1941 |
| 76 (Gloucestershire) Heavy Anti-Aircraft Regiment – from 46 Anti-Aircraft Brigade by Dec 41; to Operation Torch by Nov 42 |
| 140 Heavy Anti-Aircraft Regiment – from 46 Anti-Aircraft Brigade by May 42 |
| 24 Light Anti-Aircraft Regiment – from 5 Anti-Aircraft Division; to India 1942 |
| 36 Light Anti-Aircraft Regiment – from 46 Anti-Aircraft Brigade on formation; to 55 Anti-Aircraft Brigade by Dec 41 |
| 47 Light Anti-Aircraft Regiment – from 9 Anti-Aircraft Division on formation; to 46 Anti-Aircraft Brigade by Dec 41 |
| 72 Light Anti-Aircraft Regiment – from 9 Anti-Aircraft Division May 42; left Jul 42, later in Operation Torch |
| 83 Light Anti-Aircraft Regiment – new unit formed Aug 41, joined Dec 41; left Jun 42 |
| 133 Light Anti-Aircraft Regiment – from 60 Anti-Aircraft Brigade Jun 42, to 46 Anti-Aircraft Brigade Jul 42 |
| 3 Searchlight Regiment – from 60 Anti-Aircraft Brigade Dec 41; converted into unbrigaded 4 (Ulster) Light Anti-Aircraft Regiment in Jan 42 |
| 66 Searchlight Regiment – from 46 Anti-Aircraft Brigade on formation |
| 68 Searchlight Regiment – from 46 Anti-Aircraft Brigade on formation |
| 76 Searchlight Regiment – from 60 Anti-Aircraft Brigade Aug 42 |