189 (Mixed) Heavy Anti-Aircraft Regiment RA (TA) was formed at Nottington House, Weymouth in March 1943. It was re-organised as a non-mixed unit in November 1944. The Regiment served in Anti-Aircraft Command for its entire existence. 189 (Mixed) Heavy Anti-Aircraft Regiment RA (TA) was disbanded in October 1945 at Hartlip, Sittingbourne.
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.
| Mar 43 | Formed | Weymouth, Dorset, UK | |
| Aug 44 |  |
6 Anti-Aircraft Group, 40 Anti-Aircraft Brigade | Southern England |
| Sep 44 | |
3 Anti-Aircraft Group, 102 Anti-Aircraft Brigade | South West England |
| Oct 44 | |
5 Anti-Aircraft Group, 43 Anti-Aircraft Brigade | North East England |
| Nov 44 |
|
Re-organised as non-mixed unit |
|
| Feb 45 | |
9 Anti-Aircraft Group, 37 Anti-Aircraft Brigade | East Anglia, UK |
| Oct 45 | Disbanded | Sittingbourne, Kent, UK |
Batteries
| Mar 43 | 575 (Mixed), 577 (Mixed) |
| Apr 43 | 575 (M), 577 (M), 670 (M), 671 (M) |
| May 43 | 575 (M), 577 (M), 671 (M), 682 (M) |
| Mar 44 | 575 (M), 577 (M), |
| Nov 44 | 434, 440, 663 |
| Dec 44 | 413, 434, 440 |
| Aug 45 | 287, 309 |