Fort Belknap Agency is a census-designated place (CDP) in Blaine County, Montana, United States.

[3] Fort Belknap Agency is located at the northern end of the reservation at the junction of U.S. Route 2 and Montana Highway 66.

It is the home of facilities such as the Fort Belknap Hospital, an office of the Bureau of Indian Affairs, the Fort Belknap Tribal Council and Tribal Police, and a highway rest area.

About 14.2% of all households were made up of individuals, and 3.2% had someone living alone who was 65 years of age or older.

Students from kindergarten to 12th grade attend public school in Harlem, Aaniiih Nakoda College offers associate degrees in eleven disciplines and vocational training in five others.

The FM radio station KGVA is licensed in Fort Belknap Agency.