Barren county is in the Pennyrile region of Kentucky. The elevation in the county ranges from 465 to 1068 feet above sea level.
In 2010 the county population was 42,173 in a land area of 487.54 square miles, an average of 86.5 people per square mile.
The equine population was 3,600 in the 2012 Kentucky Equine Survey.
Barren county was named for the grasslands, known as the barrens, that cover the northern part of the county.