Nelson county is located in the western end of the Bluegrass region of Kentucky, extending into the hilly western knobs. It was formed in 1784 while a part of Virginia and named for Thomas Nelson, a Virginia governor. The county seat is Bardstown. The population of the county in 1990 was 29,710.

Many of the early settlers in the county were Roman Catholic and a diocese was established in Bardstown in 1808, where the St. Joseph Proto-Cathedral was completed about 1825. Nelson county is home to the Abbey of Gethsemani and the Sisters of Charity of Nazareth.

Whiskey has been produced commercially in Nelson county since 1844 and it is still home to several distilleries. The Oscar Getz Museum of Whiskey History is located in Bardstown.