|Prince Fatafehi Tu'ipelehake|
|Prince of Tonga|
|10th Premier of Tonga|
|In office||16 December 1965 - 22 August 1991|
|Monarch||Tāufaʻāhau Tupou IV|
|Predecessor||Crown Prince Tāufaʻāhau|
|Successor||Hon. Baron Siaosi Vaea|
7 January 1922|
Royal Palace, Nuku'alofa, Tonga
10 April 1999 77) (aged|
|Spouse||Melenaite Tupoumoheofo Veikune|
Princess Mele Siu`ilikutapu|
Princess 'Elisiva Fusipala Vaha'i
Prince `Uluvalu Takeivulangi
Princess Lavinia Mata
Prince Viliami Tupoulahi Mailefihi
|Father||Hon. Viliami Tungī Mailefihi|
|Mother||Sālote Tupou III|
Sione Ngū Manumataongo Tukuʻaho (7 January 1922 – 10 April 1999), also known as The Prince Fatafehi Tu'ipelehake, was the youngest son of HM The Queen Sālote Tupou III and was educated in Tonga and Australia. Tu'ipelehake is a traditional very high-ranking Tongan title.
Tu'i Pelehake attended Newington College, Sydney, (1941–1942) and Gatton Agricultural College, Queensland, Australia. Fatafehi married Melenaite Tupoumoheofo Veikune (13 November 1924 — 16 March 1993) on the same day as his older brother, the Crown Prince (in that time still called Tupoutoʻa-Tungī) married Halaevalu Mataʻaho ʻAhomeʻe. That was the famous double royal wedding (taʻane māhanga) of 10 June 1947. He received the title Tuʻi Pelehake (Fatafehi) from his mother (Queen Salote) in 1944, and he also received the runner up highest title of Tonga of Tuʻi Faleua (king of the second house).
From a non-traditional side, he was conferred an honorary CBE. He inherited from his mother an artistic side; he was a well-known poet and composer.
His career was with his brother in the government. His first assignment was as governor of Vavaʻu (1949–1952), later of Haʻapai (1952–1953), next he held various ministerial portfolios in cabinet, until he took over as Prime Minister of Tonga when his brother had to vacate the post on becoming king in 1965. He remained in this post until he had to withdraw in 1991 because of serious health problems. His last years were spent in a wheelchair on a life support system.
He kept the both titles of Tuʻi Pelehake and Tuʻi Faleua for so many years, that they became synonymous with him. But after his death, only the former was conferred to his son, while the latter returned to the king.
Besides his son who inherited his positions, he also had four daughters and two sons :
- Princess Mele Siu`ilikutapu Kalaniuvalu Fotofili,
- Princess 'Elisiva Fusipala Vaha'i,
- Prince `Uluvalu Takeivulangi (Late Tu`ipelehake),
- Princess Lavinia Mata `o Taone Ma`afu,
- Princess Sinaitakala `Ofeina-`e-he Langi Fakafanua, who is the mother of the Crown Princess of Tonga Princess Sinaitakala Tuku'aho whom she married her double second cousin the son of queen consort, Queen Nansipau'u and Tupou VI, the Crown Prince Tupoutoʻa ʻUlukalala.
- Prince Viliami Tupoulahi Mailefihi (Late Tu'ipelehake).
- Prince Tu'ipelehake (formerly as Hon. Viliami Sione Ngu Takeivulai Tuku'aho, the only son of late Tu'ipelehake Mailefihi) married to HSH Princess Cassandra Tu'ipelehake (formerly as Hon. Cassandra Vaea Tuku'aho) and they have two children: a son, Hon. Siaosi Tupoulahi Tu'ipelehake and a daughter, Hon. Melenaite Tupoumoheofo Tu'ipelehake.
- Tonga: Knight Grand Cross with Collar of the Royal Order of Pouono (KGCCP)
- Tonga: Knight Grand Cross of the Order of the Crown of Tonga (KGCCT)
- Tonga: Recipient of the Royal Tongan Medal of Merit (RTMM)
- Tonga: Recipient of the King Tāufaʻāhau Tupou IV Silver Jubilee Medal
- United Kingdom: Knight Commander of the Order of the British Empire
- United Kingdom: Recipient of the Queen Elizabeth II Coronation Medal