[2] The county was formed in 1842 and named for John Boyle (1774–1835), a U.S. Representative, chief justice of the Kentucky Court of Appeals, and later federal judge for the District of Kentucky,[3] and is part of the Danville, KY Micropolitan Statistical Area.

It is named for John Boyle, Congressman, Chief Justice of the Kentucky Court of Appeals, and U.S. District Judge.

Associate Justice of the Supreme Court of the United States John Marshall Harlan, a supporter of civil rights and the sole dissenter in the Civil Rights Cases and Plessy v. Ferguson, was born in Boyle County in 1833.

[5] As of the census[11] of 2000, there were 27,697 people, 10,574 households, and 7,348 families residing in the county.

27.10% of all households were made up of individuals, and 12.10% had someone living alone who was 65 years of age or older.

The county voted "No" on 2022 Kentucky Amendment 2, an anti-abortion ballot measure, by 53% to 47% despite backing Donald Trump with 61% of the vote to Joe Biden's 37% in the 2020 presidential election.

Since the start of the 21st Century, the county has voted on par with the state of Kentucky as a whole.