Biddle is an unincorporated community in southeastern Powder River County, Montana, United States, near the Little Powder River. It lies along Highway 59 south of the town of Broadus, the county seat of Powder River County. Its elevation is 3,337 feet (1,017 m), and it is located at 45°5′58″N 105°20′18″W / 45.09944°N 105.33833°W / 45.09944; -105.33833 (45.0994302, -105.3383260). A post office was established in Biddle in 1916.