Doniphan is a city in Ripley County, Missouri, United States. The population was 1,932 at the 2000 census. It is the county seat of Ripley County.
Doniphan is located at 36°37′20″N 90°49′20″W / 36.62222°N 90.82222°W / 36.62222; -90.82222 (36.622106, -90.822179). According to the United States Census Bureau, the city has a total area of 1.4 square miles (3.5 km²), all of it land.
Doniphan, Missouri is best known for its placement at the heart of the Current River, one of the cleanest rivers in the United States. It draws tourism and is a main attraction of the town.