See also: Ulster Defence Regiment.
See also: List of battalions and locations of the Ulster Defence Regiment.
| Unit Name: | 2nd/11th (County Armagh) Battalion, Ulster Defence Regiment |
| Dates: | 1991–1992 |
| Country: |  United Kingdom |
| Branch: | British Army |
| Type: | Infantry battalion |
| Role: | Internal Security |
| Size: | 750 |
| Garrison: | Lisburn |
| Garrison Label: | Regimental Headquarters |
| March: | (Quick) Garryowen & Sprig of Shillelagh. (Slow) Oft in the Stilly Night |
| Motto: | "Quis Separabit" "Who Shall Separate Us?" |
| Commander1: | First: General Sir John Anderson GBE, KCB, DSO. Last: General Sir Charles Huxtable, KCB, CBE, DL |
| Commander1 Label: | Colonel Commandant |
| Commander2: | Colonel Sir Dennis Faulkner CBE |
| Commander2 Label: | Colonel of the Regiment |
The 2nd//11th (County Armagh) Battalion, Ulster Defence Regiment was formed in 1991 as a result of an amalgamation between the 2nd Battalion Ulster Defence Regiment and the 11th Battalion Ulster Defence Regiment. The resultant 2/11 UDR was subsumed into the Royal Irish Rangers in 1992 as part of the Options for Change amalgamations and was renamed the 6th Battalion Royal Irish Regiment.