Sidney is a city located in the state of Montana within the United States. It serves as the county seat for Richland County and is situated less than 10 miles west of the North Dakota border.
The city is positioned along the Yellowstone River and sits approximately midway between Glendive, Montana, and Williston, North Dakota. According to census data, the population was 6,346 in 2020 and was estimated to be 6,031 in 2024.