Harrison is an unincorporated community and census-designated place (CDP) in Madison County, Montana, United States.

The town began as "Ferguson", a stage stop on the road to Virginia City.

Eventually the town was called Harrison after an early settler, Henry C.

[4] Harrison is located in northeastern Madison County and U.S. Route 287 passes through town, leading northeast 20 miles (32 km) to Three Forks and south 26 miles (42 km) to Ennis.

According to the U.S. Census Bureau, the Harrison CDP has an area of 0.18 square miles (0.47 km2), all land.

The racial makeup of the CDP was 96.91% White, 1.85% Native American, 0.62% Asian, and 0.62% from two or more races.