Mayfield serves as the county seat of Graves County in Kentucky. where is mayfield Kentucky? Situated in the state’s southwestern corner, the city is 190 miles southeast of St. Louis, Missouri, and 141 miles northwest of Nashville, Tennessee. Jackson Purchase Medical Center, located at 1099 Medical Center Cir, can be found here. The Wooldridge Monuments, a group of historical markers, can be located in the city’s Maplewood Cemetery.