Susuga Tuilaʻepa Lupesoliai Neioti Aiono Saʻilele Malielegaoi is a Samoan politician and economist who served as the sixth prime minister of Samoa from 1998 to 2021. Tuilaʻepa is Samoa's longest serving prime minister and was leader of the opposition from 2021 to 2022. Since 1998, he has led the Human Rights Protection Party (HRPP). Tuilaʻepa first entered parliament in 1981 when he won a by-election to represent the electorate of Lepā. He also served as deputy prime minister and minister of finance in the government of Prime Minister Tofilau Eti Alesana, and also held the portfolios of Tourism and Trade, Commerce & Industry.

The prime minister of the Independent State of Samoa is the head of government of Samoa. The prime minister is a member of the Legislative Assembly, and is appointed by the O le Ao o le Malo for a five-year term. Since independence in 1962, a total of seven individuals have served as prime minister. The incumbent was disputed due to the 2021 constitutional crisis, when Tuila'epa Sa'ilele Malielegaoi refused to accept the results of the 2021 general election. On 23 July 2021, the Samoan Court of Appeal ruled that the Faʻatuatua i le Atua Samoa ua Tasi (FAST) party had been in government since 24 May. Tuila'epa then conceded defeat, resulting in FAST party leader Fiamē Naomi Mataʻafa becoming prime minister.