Rainsville is a small unincorporated community in Pine Township, Warren County, in the U.S. state of Indiana. As of the 2020 census, Rainsville had a population of 28.
Rainsville was platted on April 16, 1833, by Isaac Rains, who had built a mill here the previous year; the town was named for him. A post office was established on February 5, 1836, and closed on September 15, 1904.
Rainsville is located southwest of Pine Village and east of U.S. Route 41. Big Pine Creek flows from Pine Village, around the north side of the town, and continues to the southwest.
It is in the Metropolitan School District of Warren County.