1 Offaly Brigade – 3 Southern Division

1 Battalion: Unit strength on 11 July 1921 was 420 all ranks, and the strength on 1 July 1922 was 215 all ranks.The companies of the 1 Battalion were located as follows: Tullamore, Gurteen, Killeigh, Ballycowan, Kilbeggan and Durrow & Bracklin.
2 Battalion: Unit strength on 11 July 1921 was 281 all ranks, and the strength on 1 July 1922 was 127 all ranks.The companies of the 2 Battalion were located as follows: Daingean, Walsh Island, Ballinagar, Cloneygowan, Ballycommon and Geashill.
3 Battalion: Unit strength on 11 July 1921 was 290 all ranks, and the strength on 1 July 1922 was 111 all ranks.The companies of the 3 Battalion were located as follows: Tyrrellspass, Killclonfert, Croghan and Rhode.
4 Battalion: This battalion was totally reorganised between the 1st and 2nd critical dates, and the companies of the reorganised 4 Battalion were all relocated.Unit strength on 11 July, 1921 was 203 all ranks, and on that date the companies of the 4 Battalion were located as follows: Edenderry, Bracknagh, Castlejordan, Rathangan, and Cushina.
Unit strength on 1 July 1922 was 114 all ranks, and on that date the companies of the 4 Battalion were located as follows: Clonaghadoo, Clonaslee and Rosenallis.

An Active Service Unit was effective with the 1 Offaly Brigade up to 11 July 1921 with a total overall strength of 51 all ranks. Personnel were attached to the A.S.U from the battalions of the brigade.