The Parker ranch was founded in 1847 and is one of the oldest ranches in the United States, pre-dating many mainland ranches in Texas and other southwestern states by more than 30 years. Spread across approximately 250,000 acres (100,000 ha) of the island, Parker Ranch is among the nation’s largest cattle ranches.

The founder of the ranch was John Palmer Parker who assisted Kamehameha I in ridding the island of feral bulls and was granted land on which he established the ranch. From 1899 to 1937 it was managed by Alfred Wellington Carter (1867–1949). The last owner of the ranch, the actor Richard Smart, died in 1992, after which the Ranch was governed by the Parker Ranch Foundation Trust.

A cowboy on the ranch is called a paniolo (Hawaiian language pronunciation of Spanish: Español), since the first cowboys were Spanish-speaking and came from California. The Hawaiian language does not have the “s” sound.

During World War II, part of the ranch was used as a United States Marine Corps training base called Camp Tarawa. The Second and Fifth Marine Divisions conducted training maneuvers there in preparation for the assault of Iwo Jima.