[2] The county was formed on December 17, 1794, from sections of Scott, Harrison, and Mason Counties[3][4] and was named for Colonel John Campbell (1735–1799), a Revolutionary War soldier and Kentucky legislator.

This was an unpopular action, however, as the overwhelming majority of residents lived in the north, along the Ohio River.

In 1840, Kenton County was created, primarily out of a significant portion of Campbell.

In 1883, after years of lobbying, the General Assembly established a special provision to allow Newport to designate a Court House District separate from the offices in Alexandria.

The special Courthouse Commission legislation led to the misconception that the county was dual seated, but Alexandria remained the sole de jure county seat.

[8] It was not until November 24, 2010, that a court ruling granted Newport equal status as a county seat.

28.60% of all households were made up of individuals, and 9.90% had someone living alone who was 65 years of age or older.

[16] Northern Kentucky University located in Highland Heights provides the area with access to higher education.

Students in the county attend one of 6 public and 2 parochial high schools.