Niangua is a city in Webster County, Missouri, United States. The population was 445 at the 2000 census. It lies three miles from Interstate 44 and five miles north of Marshfield. Niangua is part of the Springfield, Missouri Metropolitan Statistical Area. United States Congressman Roy Blunt was born in Niangua. Evangelist and gospel singer, Scott Fraker is a graduate of Niangua High School.