| Campanha Ocidental | |
| Type: | Micro-region |
| Subdivision Type: | Country |
| Subdivision Name: | Brazil |
| Subdivision Type1: | State |
| Subdivision Name1: | Rio Grande do Sul |
| Subdivision Type2: | Mesoregion |
| Subdivision Name2: | Sudoeste Rio-Grandense |
| Area Total Km2: | 31,125 |
| Population Density Km2: | auto |
| Parts Type: | Municipalities |
| Parts Style: | para |
| P1: | 10 |
The Campanha Ocidental micro-region (Microrregião de Campanha Ocidental, meaning the western fields in Portuguese) is a microregion in the western part of the state of Rio Grande do Sul, Brazil. The area is 31,125.429 km2 making it the largest micro-region in the state nearly covering one-tenth of the entire state, much of the central and eastern portions remain underpopulated.
The microregion consists of the following municipalities:[1]