thumb|[[Horse's Ghost at the fair, Poplar, MT]]
thumb|Poplar Indian Days Pow Wow in 2022
Poplar is a city in Roosevelt County, Montana, United States. The population was 758 at the 2020 census. It is the tribal headquarters for the Fort Peck Indian Reservation, though Wolf Point is the most populous. The reservation is home to both the Assiniboine and Sioux Tribes, two distinct American Indian Nations.
The U.S. Army constructed Camp Poplar here in the 1870s to oversee the reservation. Poplar became reservation headquarters after the military abandoned the camp in 1893.
Poplar hosts a Native American Pow Wow called Poplar Indian Days every year, the first weekend in September that is well attended by locals and traveling dancers with prizes for dancers and drummers.
Geography
According to the United States Census Bureau, the city has a total area of , all land. The Poplar River joins the Missouri River near town.
Climate
According to the Köppen Climate Classification system, Poplar has a semi-arid climate, abbreviated "BSk" on climate maps.