Billings County is a county in the U.S. state of North Dakota. As of the 2020 census, the population was 945, and was estimated to be 1,071 in 2025,
The Territorial legislature authorized the creation of Billings County on February 10, 1879, naming it for Northern Pacific Railway president Frederick H. Billings. It was organized on May 4, 1886. The original county boundary was significantly altered by actions in 1883, 1885, 1887, 1896, 1901, and 1904. Its most significant alterations came in 1907 (Bowman County partitioned off), 1912 (Golden Valley County partitioned off), and 1914 (Slope County partitioned off).
Geography
The Little Missouri River flows northward through the western portion of the county. Bullion Creek flows eastward into the southwestern corner of the county to discharge into the Little Missouri River.
Billings County terrain consists of rugged semi-arid hills in its western portion, giving way to more level ground in the east. The terrain slopes to the east and south, with its highest terrain along its west boundary line, at ASL.
According to the United States Census Bureau, the county has a total area of , of which is land and (0.40%) is water. It is the 28th largest county in North Dakota by total area. The South Unit of Theodore Roosevelt National Park lies in the central part of the county, just north of Medora.
Major highways
- 25px Interstate 94
- 25px U.S. Highway 85
Adjacent counties
- McKenzie County – north
- Dunn County – northeast
- Stark County – east
- Slope County – south
- Golden Valley County – west
Protected areas
- Little Missouri National Grassland (part)
- Rough Rider State Park
- Theodore Roosevelt National Park (South Unit)