Union County is a county in the U.S. state of Kentucky. As of the 2010 United States census, the population was 15,007. Its county seat is Morganfield. The county was created effective January 15, 1811. The county is located on the left bank of the Ohio River opposite its confluence with the Wabash River.

Area: 363.4 mi²

Founded: 1811

Population: 13,544 (2021)

County seat: Morganfield

Cities: Morganfield, Sturgis, Uniontown, Waverly