The Cincinnati metropolitan area, informally known as Greater Cincinnati, is a metropolitan area that includes counties in the U.S. states of Ohio, Kentucky, and Indiana around the Ohio city of Cincinnati. The United States Census Bureau's formal name for the area is the Cincinnati-Middletown Metropolitan Statistical Area. As of the 2010 U.S. Census, this MSA had a population of 2,130,151, the largest metropolitan area involving Ohio and 27th largest in the United States.