161 (Mixed) Heavy Anti-Aircraft Regiment RA (TA) was formed at Park Gate, Sheffield in June 1942. It became a non-mixed Regiment in August 1945. The Regiment served in the UK for its entire existence. 161 (Mixed) Heavy Anti-Aircraft Regiment RA (TA) was considered a new War Formed unit in January 1947 and re-designated in the April as 98 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.
| Jun 42 | Formed | Sheffield, Yorkshire, UK | |
| Aug 42 |  |
5 Anti-Aircraft Group, 41 Anti-Aircraft Brigade | East Anglia, UK |
| Feb 43 | |
5 Anti-Aircraft Group, 39 Anti-Aircraft Brigade | East Anglia, UK |
| May 43 | GHQ Reserve, 103 Anti-Aircraft Brigade | East Anglia, UK | |
| Jun 43 | |
63 Anti-Aircraft Brigade, Diver defences | East Anglia, UK |
| Aug 45 | Re-organised as non mixed regiment |
Batteries
| Jun 42 | 447 (Mixed), 448 (Mixed) |
| Jul 42 | 447 (M), 448 (M), 558 (M) |
| Nov 42 | 447 (M), 448 (M), 558 (M), 593 (M) |
| Feb 44 | 447 (M), 448 (M), 558 (M) |
| Dec 44 | 447 (M), 448 (M), 517 (M) |