In the United States the term metropolitan government is most frequently used to describe a system of municipal government in which most or all of the functions of a government of a county are combined with those of its principal city. This plan is used to reduce redundant offices, laws and regulations, and sometimes to consolidate municipal enterprise operations such as utilities. It also tends to minimize jurisdictional disputes and make possible more comprehensive planning and zoning. Cities which have taken this step include Nashville, Tennessee, Miami, Florida, Lexington, Kentucky, Jacksonville, Florida, Louisville, Kentucky, and several others. This system is often informally referred to as "metro". See consolidated city-county.

It could be argued that a truly "metropolitan" form of government would actually involve the entire metropolitan area of a major city, not just the county in which the major city is primarily located. While this would seem to be true, this is rare in practice, largely because U.S. counties and their politicians are traditionally very jealous guardians of their powers and very wary about developments that would tend to weaken or eliminate them. While there are many successful regional transit, utility, and planning agencies, there is very little in the U.S. of what might be called metropolitan government in its purest sense. Perhaps the arrangement closest to this is the one in Portland, Oregon where there is in fact a Metro agency created by and responsible to the voters of a multi-county area. That this practice should spread to other areas would seem to be common sense, but political realities tend to prevent it in most instances. The creation of such a body requires a very major commitment of time and effort by many private citizens and business leaders as well as politicians, and an electorate fairly concerned about municipal issues. Most voters in the U.S. are not deeply involved in politics, particularly at the local level, and discussions of most local issues will not generate much involvement in most areas until the citizens are being directly effected by a particular issue, at which point it may well be too late to do anything to change it. General discussions about how to improve local government rarely occur, and are widely ignored when they do. Until and unless this situation changes, there will be very few examples of true "metropolitan government" in the U.S.

Another issue will tend to make true metropolitan government more difficult to achieve, or at least temper its success. Many large metropolitan areas cross state borders, making cooperation more difficult because the United States Constitution requires Congressional approval of any agreement between states (Article I, Section 10). This in fact has somewhat tempered the success of Portland's Metro agency; it operates only on the Oregon side of the Columbia River (admittedly, the side with the large majority of the region's population) and not on the Washington side.

Often, the aversion to another level of government leads municipalities to form coalitions — essentially governmental organizations which are not empowered with any lawmaking or law enforcement powers. This is the case in the Atlanta metropolitan area, where the Atlanta Regional Commission (ARC) studies and makes recommendations on the impact of all major construction and development projects on the region, but generally cannot stop them. The Georgia Regional Transportation Authority (GRTA) is a true government agency of the state of Georgia, and does control some state transportation monies to the cities and counties, but otherwise has very little authority beyond this small power of the purse.