Siaosi (George) Manumataongo ʻAlaivahamamaʻo ʻAhoʻeitu Konstantin Tukuʻaho[1] (born 17 September 1985) is the Crown Prince of Tonga.

Tupoutoʻa ʻUlukalala became heir apparent to the throne in March 2012 upon the accession of his father, Tupou VI, as King of Tonga.

[4] On 12 July 2012, Crown Prince Tupoutoʻa ʻUlukalala married his double second cousin, Sinaitakala Fakafanua, in a wedding attended by 2,000 people.

[2] The marriage between the Crown Prince and Fakafanua caused controversy over the continued practice of marrying closely related cousins.

Frederica Tuita, who is ninth in line to the throne, openly condemned the union, calling the royal arranged marriage "extremely arrogant and only perpetuated the motive behind social climbers".

[11] His fourth child and third daughter, Princess Salote Mafileʻo Pilolevu, was born on 25 February 2021 at Calvary Public Hospital Bruce in Canberra.