Alchesay High School is a public high school on the Fort Apache Indian Reservation in Whiteriver, Arizona, Navajo County.

It was founded in 1956 and named after Chief Alchesay, who was a key person in the formation of the White Mountain Apache tribe.

(More than half of the students at Alchesay are White Mountain Apache.)

It is not on its original campus site: the old "white house" school was abandoned for the old Northland Pioneer College building (now in renovations to be used as the elementary school).

Eight years later in 2010 one student received the Gates Millennium Scholarship as well as four more recipients in 2011.