Kamehameha III (born Kauikeaouli) (1813–1854) was the King of Hawaii from 1825 to 1854. His full Hawaiian name was Keaweaweʻula Kīwalaʻō Kauikeaouli Kaleiopapa and then lengthened to Keaweaweʻula Kīwalaʻō Kauikeaouli Kaleiopapa Kalani Waiakua Kalanikau Iokikilo Kīwalaʻō i ke kapu Kamehameha when he ascended the throne.

Under his reign Hawaii evolved from an absolute monarchy to a Christian constitutional monarchy with the signing of both the 1840 Constitution and 1852 Constitution. He was the longest reigning monarch in the history of the Kingdom, ruling for 29 years and 192 days, although in the early part of his reign he was under a regency by Queen Kaʻahumanu and later by Kaʻahumanu II. His goal was the careful balancing of modernization by adopting Western ways, while keeping his nation intact.