Nelson county is in the Western Knobs region of Kentucky. The elevation in the county ranges from 390 to 1090 feet above sea level.
In 2010 the county population was 43,437 in a land area of 417.51 square miles, an average of 104.0 people per square mile.
The equine population was 2,800 in the 2012 Kentucky Equine Survey.
Nelson county was formed while the territory was part of Virginia and named for Thomas Nelson, a Virginia governor and signer of the Declaration of Independence.
Many of the early settlers in the county were Roman Catholic and a diocese was established in Bardstown in 1808, where the Saint Joseph Proto-Cathedral was completed about 1825. Nelson county is home to the Abbey of Gethsemani and the Sisters of Charity of Nazareth.