Northern Kentucky is generally agreed to consist of Kentucky's three northernmost counties: Boone, Kenton and Campbell. Each has at least one major center of population: Florence in Boone County; Covington in Kenton County; and Newport and Fort Thomas in Campbell County. Immediately on the other side of the Ohio River is Cincinnati, Ohio. However, the entire region is densely populated, with these cities surrounded by many smaller towns which have little other than a city limit sign between them. The southernmost parts of the three counties are still primarily rural in nature but are rapidly being consumed by urban sprawl. Combined with part of Indiana, and Southwestern Ohio, it is a part of The Greater Cincinnati Metropolitan Statistical Area, with a population of over 2 million.

Historically, the area was a bedroom community of Cincinnati, served by ferry service across the Ohio River until the completion of the John A. Roebling Suspension Bridge (prototype of the famous Brooklyn Bridge) in the late 1880s, whereupon land values in the areas near the river quadrupled overnight.

Beginning in the 1970s, many factors combined to create major growth. The proximity to Cincinnati, the completion of I-75, the nexus of rail service and river traffic, creation of several industrial parks, and the growth of Cincinnati/Northern Kentucky International Airport (located near Hebron, in northeastern Boone County near the Kenton County line) drew many industries into the area. Its geographically central location (within 800 miles of 80% of the US population) makes it ideal for distribution centers, and those shipping all over the US.