Wordorigins.org

Hawaii, obviously, is the native name for the island state. Havaiki in the Marquesan tongue is the mythical homeland of the Polynesians. The Marquesans were likely the ones who first settled on the islands and brought the name with them.

Captain James Cook was the first European to visit the islands in 1776. He dubbed them the Sandwich Islands, after the Earl of Sandwich. Yes, he of culinary fame.

(Sources: Illustrated Dictionary of Place Names; Webster’s Third New International Dictionary)