In United States local government, a consolidated city-county is formed when one or more cities and their surrounding county (parish in Louisiana, borough in Alaska) merge into one unified jurisdiction. As such it has the governmental powers of both a municipal corporation and an administrative division of a state.

A consolidated city-county is different from an independent city, although the latter may result from consolidation of a city and a county and may also have the same powers as a consolidated city-county. An independent city is a city not deemed by its state to be located within the boundary of any county and considered a primary administrative division of its state. A consolidated city-county differs from an independent city in that the city and county both nominally exist, although they have a consolidated government, whereas in an independent city, the county does not even nominally exist. Furthermore, a consolidated city-county may still contain independent municipalities maintaining some governmental powers that did not merge with the rest of the county.

Not considering Hawaii, which has no independent municipalities, the Midwest and Upper South have the highest concentration of large consolidated city-county governments in the United States, including Indianapolis, Indiana; Nashville, Tennessee; Louisville, Kentucky; Kansas City, Kansas; and Lexington, Kentucky. Currently, the largest consolidated city-county in the United States by population is Philadelphia, Pennsylvania, while the largest by land area is Sitka, Alaska.