Logan County is situated in south central Kentucky, covering 557 square miles in the Pennyroyal Plateau area. Logan County shares borders with Todd County to the west, Muhlenberg County to the northwest, Butler County to the north, Warren County to the northeast, Simpson County to the southeast, and Robertson County, Tennessee to the south.

The county is home to approximately 27,000 residents living in the cities of Adairville, Auburn, Lewisburg, and Russellville; as well as the communities of Agnes, Anderson, Beechland, Cave Springs, Chandlers Chapel, Cooperstown, Corinth, Costelow, Crossroad, Danby, Deer Lick, Dennis, Diamond Springs, Dot, Edwards, Epleys, Everett, Ferguson, Gasper, Gordonsville, Happy Hollow, Henryville, Hilltop, Hollow Bill, Homer, Insco, Jerico, Justice, Keysburg, Lickskillet, Lost City, Mortimer Station, Mosley Pond, Oakville, Old Volney, Olmstead, Richelieu, Rogers, Schochoh, South Union, Spa, Whippoorwill, and Wolf Lick.