158 (Mixed) Heavy Anti-Aircraft Regiment RA (TA) was formed at Dunfermline in May 1942. It became a non-mixed Regiment in March 1946. The Regiment served in Anti-Aircraft Command for its whole existence. 158 (Mixed) Heavy Anti-Aircraft Regiment RA (TA) was considered a new War Formed unit in January 1947 and re-designated in the April as 111 Heavy Anti-Aircraft Regiment RA.
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.
| May 42 | Formed | Dunfermline, Fife, UK | |
| Aug 42 |  |
3 Anti-Aircraft Division, 36 Anti-Aircraft Brigade | Edinburgh, UK |
| Aug 43 |  |
6 Anti-Aircraft Group, 51 Anti-Aircraft Brigade | Edinburgh, UK |
| Nov 43 | |
6 Anti-Aircraft Group, 42 Anti-Aircraft Brigade | Edinburgh, UK |
| Apr 44 | |
5 Anti-Aircraft Group, 30 Anti-Aircraft Brigade | East Midlands, UK |
| Re-organised as a non-mixed regiment in 1946 |
Batteries
| Jun 42 | 540 (Mixed), 541 (Mixed), 548 (Mixed), |
| Sep 42 | 540 (M), 541 (M), 548 (M), 572 (M) |
| Dec 44 | 540 (M), 541 (M) |
| Feb 45 | 510 (M), 540 (M), 541 (M) |