The Fourth Battle of Tucson was a raid during the lengthy wars between Spanish colonists in Arizona and its region and Apache Indians.

At break of day, on March 21, 1784, a force of no more than 500 Apaches and Navajos attacked Spanish cavalry guards protecting a herd of livestock at the Presidio San Augustin del Tucson in southern Arizona.

The Spanish sentries were under the command of Ensign Don Juan Carrillo when hundreds of mounted Navajo and Apache warriors attacked their position which guarded a livestock pen.

Under the orders of Lieutenant Tomás Equrrola, reinforced with thirty Pima scouts from the neighboring towns of Tupson and San Xavier.

Another battle began and Lieutenant Equrrola's men killed fourteen warriors, among them the native commander, Chief Chiquito.