It was named for John Adair, a general in the War of 1812, and the eighth Governor of Kentucky.

[1] As of the 2010 United States census, there were 7,682 people, 3,292 households, and 2,148 families residing in the county.

There were 3,698 housing units at an average density of 6.5 per square mile (2.5/km2).

[10] In terms of ancestry, 42.9% were German, 12.6% were Irish, 11.9% were English, 6.7% were Danish, and 6.4% were American.

[13] As of 2000[update], 67.9% of the population (5,597) had a declared religious affiliation, in every case Christian.