517 (Thames & Medway) Coast Regiment RA(TA) was formed from a part of the Thames & Medway Heavy Regiment RA(TA), in July 1940. RHQ was placed in to suspended animation in June 1945 and was disbanded in January 1947.
| Jul 40 | Formed from part of Thames & Medway Heavy Regiment | |
| Jul 40 | Home Forces | UK |
| Dec 42 | Thames Fire Command | Canvey Island, Essex, UK |
| Jun 45 | Suspended animation |
Batteries
| Jul 40 | A, B |
| Dec 40 | A, 332, 356, 419 |
| Apr 41 | 167, 168, 332, 356, 419 |
| Sep 41 | 167, 168, 332, 356, 357, 419 |
| Oct 41 | 109, 167, 168, 332, 356, 419 |
| Feb 42 | 167, 168, 356, 419, 425 |
| Mar 43 | 168, 286, 356, 419, 425 |
| Apr 44 | 220, 356, 419, 425 |
