Valliant is a town in McCurtain County, Oklahoma, United States. The population was 754 at the 2010 census.Valliant was founded June 2, 1902, and named for Frank W. Valliant, a chief divisional engineer for the Arkansas & Choctaw Railroad being constructed in the area at that time. Valliant is famous for its annual Watermelon Festival at the City Park. The primary employer in town is International Paper, which operates a containerboard mill.