Dayton () is the sixth-largest city in the state of Ohio and the county seat of Montgomery County. A small part of the city extends into Greene County. In the 2010 census, the population was 141,759, and the Dayton metropolitan area had 799,232 residents, making it Ohio's fourth-largest metropolitan area, after Cleveland, Cincinnati, and Columbus, and the 63rd-largest in the United States. The Dayton-Springfield-Greenville Combined Statistical Area had a population of 1,080,044 in 2010, making it the 43rd-largest in the United States. Dayton is within Ohio's Miami Valley region, just north of the Cincinnati–Northern Kentucky metropolitan area.
Ohio's borders are within 500 miles (800 km) of roughly 60 percent of the country's population and manufacturing infrastructure, making the Dayton area a logistical centroid for manufacturers, suppliers, and shippers. Dayton also hosts significant research and development in fields like industrial, aeronautical, and astronautical engineering that have led to many technological innovations. Much of this innovation is due in part to Wright-Patterson Air Force Base and its place in the community. With the decline of heavy manufacturing, Dayton's businesses have diversified into a service economy that includes insurance and legal sectors as well as healthcare and government sectors.
Along with defense and aerospace, healthcare accounts for much of the Dayton area's economy. Hospitals in the Greater Dayton area have an estimated combined employment of nearly 32,000 and a yearly economic impact of $6.8 billion. It is estimated that Premier Health Partners, a hospital network, contributes more than $2 billion a year to the region through operating, employment, and capital expenditures. In 2011, Dayton was rated the #3 city in the nation by HealthGrades for excellence in healthcare. Many hospitals in the Dayton area are consistently ranked by Forbes, U.S. News & World Report, and HealthGrades for clinical excellence.
Dayton is also noted for its association with aviation; the city is home to the National Museum of the United States Air Force and is the birthplace of Orville Wright. Other well-known individuals born in the city include poet Paul Laurence Dunbar and entrepreneur John H. Patterson. Dayton is also known for its many patents, inventions, and inventors, most notably the Wright brothers' invention of powered flight. In 2008, 2009, and 2010, Site Selection magazine ranked Dayton the #1 mid-sized metropolitan area in the nation for economic development. Also in 2010, Dayton was named one of the best places in the United States for college graduates to find a job.