Obion County is a county located in the northwest corner of the U.S. state of Tennessee. As of the 2020 census, the population was 30,787. The county seat is Union City. The county was formed in 1823 and organized in 1824. It was named after the Obion River.

Hickman County is a county located in the U.S. state of Kentucky. As of the 2020 census, the population was 4,521, making it the third-least populous county in Kentucky. Its county seat is Clinton. The county was formed in 1821. It is the least densely populated county in the state and is a prohibition or dry county.