A total of approximately 4,000 acres were listed for sale in Obion County, Tennessee, recently, representing a total value of $59 million in Obion County land for sale. Obion County ranks 49th in the Volunteer State for the total acreage of land currently advertised for sale. Union City featured the most land for sale. Obion County is the 28th largest county (555 square miles) in Tennessee. It's located in the West Tennessee region of the state.