Bruneau is an unincorporated community in Owyhee County in the southwestern part of the U.S. state of Idaho. The mouth of the Bruneau River is to the northwest and Bruneau Sand Dunes State Park is to the east.
Bruneau is located at 42°52′50″N 115°47′50″W / 42.88056°N 115.79722°W (42.8804516, -115.7973081),
at an elevation of 2,549 feet (777 m) above sea level.
According to the Köppen Climate Classification system, Bruneau has a semi-arid climate, abbreviated "BSk" on climate maps.
State Highway 51 northbound crosses the Snake River and continues to Mountain Home in Elmore County; southbound it becomes Nevada Route 225 at the border and continues to Elko. State Highway 78 heads northwest within Owyhee County to Grand View, Murphy, and Marsing. Eastbound SH-78 crosses the Snake River and links through Hammett to Interstate 84.