Prince Kūhiō Day is an official holiday in the state of Hawaiʻi in the United States.^[1] It is celebrated annually on March 26, to mark the birth of Prince Jonah Kūhiō Kalanianaʻole — heir to the throne of the Kingdom of Hawaiʻi, prince of the House of Kalākaua, and later territorial delegate to the United States Congress.^[2] As Delegate, Kuhio authored the first Hawaii Statehood bill in 1919. He also won passage of the Hawaiian Homes Act, creating the Hawaiian Homes Commission and setting aside 200,000 acres (810 km²) of land for Hawaiian homesteaders.

It is one of only two holidays in the United States dedicated to royalty, the other being Hawaiʻi's King Kamehameha Day June 11.^[1]