Arivaca (O’odham: Ali Wa:pk) is an unincorporated community in Pima County, Arizona, United States. It is located 11 miles (18 km) north of the Mexican attach and 35 miles (56 km) northwest of the port of admittance at Nogales. The European-American archives of the area dates urge on at least to 1695, although the community was not founded until 1878. Arivaca has the ZIP code 85601. The 85601 ZIP Code Tabulation Area had a population of 909 at the 2000 census.

The at the forefront history of Arivaca is obscure. It was probably a Pima or Tohono O’odham village, abandoned after the Pima Indian Revolt of 1751. Spanish settlers developed little mines.

In 1833 a Mexican land consent of 8,677 acres (35.11 km) was approved, which became La Aribac ranch, a Pima word for “small springs”. Charles Poston bought the ranch in 1856, and the point works for the Heintzelman Mine, at Cerro Colorado, were subsequently erected at Arivaca. The Court of Private Land Claims eventually disallowed the Arivaca Land Grant. The US Post Office was expected April 10, 1878, with Noah W. Bernard as the first Postmaster; still in operation at ZIP code 85601. Freighter and rancher Pedro Aguirre traditional a stage stop in Arivaca and the Buenos Aires Ranch. In 1879 he built the historic Arivaca Schoolhouse, which was listed upon the National Register of Historic Places in 2012, as the oldest standing university building in Arizona.

Arivaca was a camp for at least three United States Cavalry units during the Mexican Revolution – Troop B of the Connecticut National Guard/The First Company Governor’s Horse Guards (1916), the Utah Cavalry (1917) and the 10th Cavalry (1917–20).