Blue Ash is a city in Hamilton County, Ohio, United States, and is an inner suburb of Cincinnati, which is located to the south. The population was 12,114 at the 2010 census.
The area that is now Blue Ash was settled circa 1791. In 1797, the first settlers built Carpenter's Run Baptist Church out of blue ash logs, giving the area its eventual name.
In the late 19th century, the Cincinnati, Lebanon and Northern Railway provided narrow gauge commuter rail service to Blue Ash.
Blue Ash was the site of Cincinnati–Blue Ash Airport from 1921 to 2012. Originally a private airfield called Grisard Field, it was sold to the City of Cincinnati in 1946, becoming Ohio's first municipal airport. Cincinnati desired to expand the airport for major commercial service through the 1950s, but Blue Ash fought the city by incorporating first as a village in 1955 and then as a city in 1961. Eventually, through Reed Hartman's Community Improvement Corporation, Cincinnati developed the surrounding area as an industrial park and golf course. The airport closed on August 29, 2012, and the property was sold to the City of Blue Ash, which opened Summit Park on the property.
In 1998, the Southwest Ohio Regional Transit Authority proposed a MetroMoves light rail system with a Green Line that would initially run 19-mile (31 km) from Blue Ash to Covington, Kentucky. A future phase would have extended the line further north to Kings Island and south to the Cincinnati/Northern Kentucky International Airport. However, MetroMoves was rejected by Hamilton County voters.