Ada ( /eɪdə/) 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. In 1817, The Ohio Shawnee Native American tribe signed the Treaty of Fort Meigs to receive reservation land at Hog Creek near Ada.
Ada is located at 40°46′8″N 83°49′20″W / 40.76889°N 83.82222°W / 40.76889; -83.82222 (40.768883, -83.822298).
According to the United States Census Bureau, the village has a total area of 1.9 square miles (4.8 km²), all of it land. The area surrounding the village is mostly farmland and small plots of forest. Hog Creek is the only waterway of note and snakes around the village to the north and the east.