Keene is a city in Cheshire County, New Hampshire, United States. The population was 23,409 at the 2010 census. It is the seat of Cheshire County.Keene is home to Keene State College and Antioch University New England. It hosted the state's annual Pumpkin Festival from 1991 until 2014. The city council refused to grant a license in 2015 following violent outbreaks by visiting college students in neighborhoods during the 2014 event.