| Conflict: | Battle of Arroyo Grande |
| Partof: | the Uruguayan Civil War |
| Date: | 6 December 1842 |
| Place: | Arroyo Grande, Entre Rios Province, Argentina |
| Result: | Blanco victory |
| Combatant1: | Blancos |
| Combatant2: | Colorados Unitarian Party |
| Commander1: | Manuel Oribe |
| Commander2: | Fructuoso Rivera |
| Strength1: | 12,000 |
| Strength2: | 7,500 |
| Casualties1: | 300 killed & wounded |
| Casualties2: | 2,000 killed 1,400 wounded |
The Battle of Arroyo Grande took place on 6 December 1842 and was a major battle of the Uruguayan Civil War.
At Arroyo Grande, the federal forces, or blancos, of Manuel Oribe defeated the colorados of Fructuoso Rivera, having been in conflict with them since 1838.
Following the battle, Oribe followed up his victory over the Colorados by marching to and besieging Montevideo thus beginning the Great Siege of Montevideo.