Oak Grove is an unincorporated community in Clackamas County, Oregon, United States, in the Portland metropolitan area. For statistical purposes, the United States Census Bureau has defined Oak Grove as a census-designated place (CDP). The census definition of the area may not precisely correspond to local understanding of the area with the same name. The population was 16,629 at the 2010 census.

Clackamas County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 421,401, making it Oregon's third-most populous county. Its county seat is Oregon City. The county was named after the native people living in the area at the time of the coming of Europeans, the Clackamas people, who are part of the Chinookan peoples.