Area code 559 is a telephone area code in the North American Numbering Plan for the central San Joaquin Valley in central California. The numbering plan area includes the counties of Fresno, Madera, Kings, and Tulare, an area largely coextensive with the Fresno and Visalia-Porterville metropolitan areas. The area code was placed in service in 1998, when its services area was split from that of area code 209.