Dewey county is located in northwestern Oklahoma with Taloga serving as the county seat.
In a distinctly rural county, the only major waterway is the Canadian River which snakes its way through the central portion of the county before exiting near the southeast corner. The North Canadian River makes a brief appearance in the northeast part of the county while Canton Lake is just across the Blaine County line to the east.
Among the sites deemed "historic" are the Dewey County Courthouse in Taloga, the McAllister House in Seiling and the Seiling Milling Company.
The county population on July 1, 1999, was 4,859, a decrease of 692 over the 1990 census.