Riverside is an unincorporated community in Ravalli County, Montana, United States. Its elevation is 3,517 feet (1,072 m), and it is located at 46.2747°N -114.1581°W (46.2746439, -114.1581505).
A post office operated in Riverside for a short time: it was established on January 16, 1889 and closed on May 28, 1895. The community once possessed a railroad station, which is no longer in existence; at various times, it was known as Riverside, Haggin, or River Siding. Today, an RV park is located in the area.