N66

N66 may refer to:

Roads

 * N66 road (Ireland)
 * Calamba–Pagsanjan Road, in the Philippines
 * Nebraska Highway 66, in the United States

Other uses

 * N66 (Long Island bus)
 * HMS Unity (N66), a submarine of the Royal Navy
 * Oneonta Municipal Airport, in Otsego County, New York, United States