Area codes 937 and 326 are telephone area codes in the North American Numbering Plan (NANP) assigned to a numbering plan area (NPA) that encompasses much of the southwestern part of the U.S. state of Ohio, including Dayton and Springfield. Area code 937 was established in September 1996, after a split of area code 513. Area code 326 was added to area code 937 in an overlay plan in March 2020.