It was named in honor of Isaac Shelby, governor of Kentucky and participant in the American Revolutionary War.

[5] As of the 2010 United States census, there were 22,363 people, 9,216 households, and 6,376 families living in the county.

There were 10,396 housing units at an average density of 13.7 per square mile (5.3/km2).

[11] In terms of ancestry, 25.5% were German, 9.9% were English, 9.8% were American, and 8.8% were Irish.

[13] The Census Bureau has defined one census-designated place (CDP) in Shelby County.