166 (Newfoundland) Field Regiment RA was formed by conversion of 57 Heavy Regiment RA(TA) in November 1941 with three batteries. 166 (Newfoundland) Field Regiment RA was disbanded in October 1945.
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.
| Nov 41 | Converted from 57 Heavy Regiment | ||
| 1 Sep 42 |  |
1 Army Group RA | Glasgow area, UK |
| Dec 42 | Embark for N Africa | ||
| Feb 43 | |
1 Army Group RA | Bone, Algeria |
| Mar 43 | |
1 Army Group RA | Djebel Bargou, Tunisia |
| Apr 43 | |
1 Army Group RA | Longstop Hill, Tunisia |
| May 43 |  |
1 Armoured Division | Bou Arada, Tunisia |
| May 43 | |
1 Armoured Division | Djebel Ressas, Tunisia |
| May 43 | 1 Army | Setif, Algeria | |
| Jul 43 |  |
Allied Forces HQ | Algeria |
| Sep 43 | |
Allied Forces HQ | Philippeville, Algeria for embarkation |
| Sep 43 | Taranto, Italy | ||
| Nov 43 |  |
8 Army | Termoli, Italy |
| Nov 43 | |
8 Army | Sangro, Italy |
| Dec 43 | |
8 Army | Frisa, Italy |
| Dec 43 | |
8 Army | Lanciano, Italy |
| Feb 44 | |
8 Army | Cassino, Italy |
| Jun 44 | |
8 Army | Chieti, Italy |
| Aug 44 | |
8 Army | River Arno, Italy |
| Sep 44 |  |
6 South African Armoured Divsion | Gothic Line, Italy |
| Feb 45 | |
8 Army | Benevento, Italy |
| Oct 45 | Disbanded |
Batteries
| Nov 41 | A, B, C |
| Mar 42 | P, Q, R |
| Jan 43 | 135, 136, 137 |
Equipment
| Nov 41 to Jul 45 | 25 pdr |