The Columbus, OH Metropolitan Statistical Area is the metropolitan area centered on the American city of Columbus, Ohio. Definitions of what is commonly referred to as the "Columbus Area" vary. According to the U.S. Census Bureau, the metropolitan area includes the counties of Delaware, Fairfield, Franklin, Hocking, Licking, Madison, Morrow, Perry, Pickaway, and Union. The population of the MSA is 1,967,066 according to census estimates, ranking third in Ohio and 32nd in the nation.