| Unit Name: | Third Fleet |
| Dates: | 1 May 1912–1914 |
| Country: |  United Kingdom |
| Branch: | Royal Navy |
| Type: | Reserve fleet |
| Size: | 2 x Battle squadrons 6 x Cruiser squadrons 3 x Local Defence Flotilla |
The Third Fleet was a reserve formation of the Royal Navy that briefly existed before the First World War.
Formed on 1 May 1912 from the 4th Division of the Home Fleet, its elderly ships were ordinarily only manned by a small maintenance crew during peacetime, but were intended to be manned by naval reservists when mobilised.[1] It was conducting a test mobilisation in July 1914 as tensions increased between Great Britain and Imperial Germany[2] and was only partially demobilised before full mobilisation was ordered on 2 August. At this time it consisted of the 7th and 8th Battle Squadrons of pre-dreadnought battleships and five squadrons of cruisers.[3]
| Rank | Flag | Name | Term | |
|---|---|---|---|---|
| Vice-Admiral Commanding Third Fleet [4] | ||||
| 1 | Vice-Admiral | December 1911-December 1913 | ||
| 2 | Vice-Admiral | December 1913-August 1914. | ||
Included [5]
| Unit | Notes | |
| 1 | 7th Battle Squadron | (8 pre-dreadnoughts) [6] |
| 2 | 8th Battle Squadron | (6 pre-dreadnoughts) [7] |
| 3 | 7th Cruiser Squadron | (5 armoured cruisers) [8] |
| 3 | 8th Cruiser Squadron | (5 armoured/protected cruisers) [9] |
| 4 | 9th Cruiser Squadron | (8 armoured/protected cruisers) [10] |
| 5 | 10th Cruiser Squadron | (7 protected cruisers)-from Training Squadron at Queenstown [11] |
| 6 | 11th Cruiser Squadron | (5 protected cruisers) [12] |
| 7 | 12th Cruiser Squadron | (4 protected cruisers) [13] |
| 8 | Devonport Local Defence Flotilla[14] | |
| 9 | Nore Local Defence Flotilla[15] | |
| 10 | Portsmouth Local Defence Flotilla[16] | |