Ada is a village in Hardin County, Ohio, United States. The population was 5,582 at the 2000 census. In 2006, the village's population was estimated at 5,841, and the 2010 census counted 5,952 people. The Wilson Sporting Goods NFL football manufacturing facility is located in Ada, and is the only leather football manufacturing facility in the United States. The National Arbor Day Foundation has qualified Ada as a Tree City USA.