Boone County is a county located on the Ohio River in the northernmost part of the Commonwealth of Kentucky. As of the 2020 census, the population was 135,968, making it the fourth-most populous county in Kentucky. Its county seat is Burlington. The county was formed in 1798 from a portion of Campbell County. and was named for frontiersman Daniel Boone. Boone County, with Kenton and Campbell Counties, is of the Northern Kentucky metro area, and the Cincinnati-Middletown, OH-KY-IN Metropolitan Statistical Area. It is the location of the Cincinnati/Northern Kentucky International Airport, which serves Cincinnati and the tri-state area.

Burlington is a census-designated place (CDP) in and the county seat of Boone County, Kentucky, United States. The population was 17,318 at the 2020 census.