Benton County, Washington

Benton County, Washington
Benton County Courthouse
Location within the U.S. state of Washington
Coordinates: 46°15′N 119°30′W / 46.25°N 119.5°W / 46.25; -119.5
Country United States
State Washington
FoundedMarch 8, 1905
Named afterThomas Hart Benton
SeatProsser
Largest cityKennewick
Area
 • Total
1,760 sq mi (4,600 km2)
 • Land1,700 sq mi (4,400 km2)
 • Water60 sq mi (160 km2)  3.4%
Population
 (2020)
 • Total
206,873
 • Estimate 
(2024)
218,190
 • Density110/sq mi (42/km2)
Time zoneUTC−8 (Pacific)
 • Summer (DST)UTC−7 (PDT)
Congressional district4th
Websitebentoncountywa.gov

Benton County is a county in the south-central portion of the U.S. state of Washington. As of the 2020 census, its population was 206,873. The county seat is Prosser, and its most populous city is Kennewick. The Columbia River demarcates the county's north, south, and east boundaries.

Benton County was created from what were then larger versions of Klickitat County and Yakima County on March 8, 1905, and was named after Missouri statesman Thomas Hart Benton.