In the United States, a principal city is the core city or cities in a metropolitan area. The largest city in each metropolitan or micropolitan statistical area is designated a "principal city." Additional cities qualify if specified requirements are met concerning population size and employment. The title of each metropolitan or micropolitan statistical area consists of the names of up to three of its principal cities and the name of each state into which the metropolitan or micropolitan statistical area extends.
of U.S. cities
|Populous cities and metropolitan areas|
In the United States and Puerto Rico, the Office of Management and Budget identifies principal cities for each Core Based Statistical Area (CBSA) and New England City and Town Area (NECTA). Principal cities are used primarily for naming CBSAs and NECTAs, as well as combined statistical areas and combined NECTAs.