186 (Mixed) Heavy Anti-Aircraft Regiment RA (TA) was formed at Llangennech, Llanelli in December 1942. The Regiment was disbanded in March 1945 at Neath.
| Dec 42 | Formed | Llanelli, Carmarthen, UK |
| Mar 45 | Disbanded | Neath, Glamorgan, UK |
Batteries
| Jan 43 | 622 (Mixed), 623 (Mixed) |
| May 43 | 622 (M), 623 (M), 643 (M), 669 (M), 680 (M) |
| May 44 | 622 (M), 623 (M), 669 (M), 680 (M) |
| Jul 44 | 622 (M), 623 (M) |