NY 326 was assigned as part of the 1930 renumbering of state highways in New York as a connector highway between Union Springs and Auburn. However, its original alignment followed Oakwood Road and Genesee Street from the hamlet of Oakwood to downtown Auburn. It was realigned in the mid-1970s to end at US 20 and NY 5 west of downtown Auburn. In 1981, NY 326 was rerouted between the hamlets of Oakwood and Half Acre to follow Half Acre Road. NY 326's former routing between the two points is now maintained by Cayuga County.