Gasconade County is a county located in the east-central portion of the U.S. state of Missouri. As of the 2020 census, the population was 14,794. The county seat has been Hermann since 1842. The county was named after the Gasconade River. The county is located on the south side of the Missouri River, which once served as the chief route of transportation in the state. It is located in the area known as the Missouri Rhineland.