Andrew County is a county located in the northwestern part of the U.S. state of Missouri. As of the 2010 U.S. Census, the county had a population of 17,291. Its county seat is Savannah. The county was organized January 29, 1841 and named for Andrew Jackson Davis, a lawyer and prominent citizen of St. Louis.Andrew County is part of the St. Joseph, MO-KS Metropolitan Statistical Area, which is included in the Kansas City-Overland, Park-Kansas City, MO-KS Combined Statistical Area.