Tupua (known as Tupua Tamasese) is a state dynasty and one of the four paramount chiefly titles of Samoa, known as the Tama-a-Aiga or 'Sons of the Great Families'). It is the titular head of one of Samoa's two great royal families - Sā Tupua, the lineage of Queen Salamasina. The 'Tupua' refers to Salamasina's descendant, King Tupua Fuiavailili, who was the first to unite both of Salamasina's descent lines in his personage and ascended to the Kingship of Samoa in c.1550, upon the death of his adoptive father, King Muagututi'a. Tupua Fuiavailili was adopted by his aunt, Fenunu'ivao (daughter of Leutele and wife of King Muagututi'a) and named as the King's successor. Tupua's rise also led to the first usage of the term "Tama-a-'aiga" by the orator polity of Leulumoega and Lufilufi, in reference to his many genealogical connections to the great families of Ātua. The 'Tamasese' part refers to his descendant Tupua Tamasese Titimaea, whose prowess in battle and generosity won favour with many of his followers and whose actions restored the Salamasina line's prestige. All subsequent Tupua title holders have thus carried the two names together since then.

Fa'amatai is the indigenous political ('chiefly') system of Samoa, central to the organization of Samoan society. It is the traditional indigenous form of governance in both Samoas, comprising American Samoa and the Independent State of Samoa. The term comprises the prefix fa'a and the word matai.