The Dayton metropolitan area is the fourth largest metropolitan area in the state of Ohio, behind the largest, Greater Cincinnati, Greater Cleveland, and Greater Columbus.

Dayton Metropolitan Area (also known as the Greater Dayton), as defined by the United States Census Bureau, is an area consisting of four counties in the Miami Valley region of Ohio and is anchored by the city of Dayton. As of 2000 it is the fourth largest metropolitan area in Ohio and the 61st largest Metropolitan Area by Population in the United States. As of the 2010 census, the MSA had a population of 841,502. The larger Dayton–Springfield–Greenville Combined Statistical Area includes Greene County, Darke County, Montgomery County, Miami County, Clark County, and Preble County and had a population of 1,072,891 according to the 2010 Census.

The Dayton-Springfield-Greenville Combined Statistical Area is a CSA in the U.S. state of Ohio, as defined by the United States Census Bureau. It consists of the Dayton Metropolitan Statistical Area (the counties of Montgomery, Greene, Miami and Preble); the Springfield Metropolitan Statistical Area (Clark County); the Urbana Micropolitan Statistical Area (Champaign County); and the Greenville Micropolitan Statistical Area (Darke County). As of the 2010 Census, the CSA had a population of 1,072,891.