Taufa'ahau Tupou IV, King of Tonga (d. 2006)
Tāufaʻāhau Tupou IV (4 July 1918 – 10 September 2006) was the King of Tonga, from the death of his mother, Queen Sālote Tupou III, in 1965 until his own death in 2006.

Immediately prior to his death, he was the fifth longest-reigning living monarch in the world after Kings Bhumibol Adulyadej of Thailand, Saqr bin Mohammed Al Qasimi of Ras al Khaimah, Queen Elizabeth II of the United Kingdom and Commonwealth Realms and Abdul Halim of Kedah.