Apayao (Ilocano: Probinsia ti Apayao) is a landlocked province in the Philippines in the Cordillera Administrative Region in Luzon. Its capital town is Kabugao.

The province borders Cagayan to the north and east, Abra and Ilocos Norte to the west, and Kalinga to the south. Prior to 1995, Kalinga and Apayao comprised a single province named Kalinga-Apayao, which was partitioned to better service the needs of individual ethnic groups.

With a population of 119,184 (as of the 2015 census)[2] covering an area of 4,413.35 square kilometres (1,704.00 sq mi),[1] Apayao is the least densely-populated province in the Philippines.