This brigade, in the unit formation as listed here, existed on the first critical date 11 July 1921 only. Prior to the second critical date of 1 July 1922 a number of units listed below were re-formed into the 2 Brigade South-West Galway.
1 Battalion (Gort): Unit strength on 11 July 1921 was 466 all ranks.The companies of the 1 Battalion were located as follows: Peterswell, Kilbracanty,  Beagh,  Derrybrien,  and Gort.
2 Battalion (Ardrahan): Unit strength on 11 July 1921 was 370 all ranks. The companies of the 2 Battalion were located as follows:  Kinvara,  Ballinderreen, Ardrahan,  Kilmacduagh,  and Killartan.
3 Battalion (Athenry): Unit strength on 11 July 1921 was 461 all ranks. The companies of the 3 Battalion were located as follows:  Athenry,  Craughwell,  Maree Oranmore,  Kilconieran,  Killimor Daly,  and Clarenbridge.