The U.S. dollar is the currency used in Hawaii. Hawaii became a U.S. state in 1959. Prior to becoming a state, Hawaii was a territory of the United States, annexed in 1898.
From the time Hawaii became a territory of the United states, the dollar has been the currency of the islands. The Kingdom of Hawaii existed for about 100 years, commencing in 1795. The Republic of Hawaii followed the Kingdom. Each of these incarnations maintained its own, unique currencies. Additionally, foreign powers occupied Hawaii during different time periods, with the currency of these nations being used on the islands.