Corvallis is a city and the seat of government of Benton County in central western Oregon, United States. It is the principal city of the Corvallis, Oregon Metropolitan Statistical Area, which encompasses all of Benton County. As of the 2020 United States Census, the population was 59,922, making it the 10th most populous city in Oregon. Corvallis is the location of Oregon State University and Good Samaritan Regional Medical Center. Corvallis is the westernmost city in the contiguous 48 states with a population larger than 50,000.

Benton County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 95,184. Its county seat is Corvallis. The county was named after Thomas Hart Benton, a U.S. Senator who advocated American control over the Oregon Country. Benton County is designated as the Corvallis, OR Metropolitan Statistical Area, which is included in the Portland–Vancouver–Salem, OR–WA Combined Statistical Area. It is in the Willamette Valley.