Princess Sālote was born on 13 March 1900 in Tonga as the only child of King George Tupou II of Tonga and his second wife, Queen Lavinia. It was an unpopular match. Queen Lavinia died of tuberculosis on 25 April 1902. Her father was urged to remarry in order to father a male heir, and he finally did so on 11 November 1909. He married 16-year-old Anaseini Takipō and together they had two daughters, one who died of convulsions at the age of six months and one who died of tubercular peritonitis at the age of 20.
At the age of 9, she was sent to live in Auckland in New Zealand for her education. She stayed for five years and only returned to Tonga for the Christmas holidays. It wasn’t until 1914 she was considered the heir as by now the hopes of the Queen producing a male heir were low. Her education was intensified at this point. She married Viliami Tungī Mailefihi on 19 September 1917, and they had three children together, including the future King Tāufa‘āhau Tupou IV. She also suffered three miscarriages. His high status (he was the heir presumptive before Sālote’s birth) made the match very popular.
She succeeded her father as Queen on 5 April 1918, just barely 18 years old. Her coronation took place on 11 October of the same year. Her husband served as her prime minister from 1923 until his death in 1941. Sālote attended the coronation of Queen Elizabeth II in 1953 in her first and only visit to Europe.
Sālote died on 16 December 1965 after a long illness. She was succeeded by her son as King Tāufaʻāhau Tupou IV. She was buried at Mala‘e Kula, the royal burial grounds in Tonga.