Tui Ātua Tupua Tamasese Efi

His Highness Le Afioga
Tui Ātua Tupua Tamasese Efi
His Highness Le Afioga Tui Ātua Tupua Tamasese Efi
O le Ao o le Malo of Samoa
	In office; 20 June 2007 – 21 July 2017; Acting: 11 May 2007 – 20 June 2007
Prime Minister	Tuila'epa Sa'ilele Malielegaoi
Preceded by	Malietoa Tanumafili II
Succeeded by	Tuimalealiʻifano Vaʻaletoʻa Sualauvi II
3rd Prime Minister of Western Samoa
	In office; 18 September 1982 – 31 December 1982
O le Ao O le Malo	Malietoa Tanumafili II
Preceded by	Va'ai Kolone
Succeeded by	Tofilau Eti Alesana
	In office; 24 March 1976 – 13 April 1982
O le Ao O le Malo	Malietoa Tanumafili II
Preceded by	Lealofi IV (acting)
Succeeded by	Va'ai Kolone
O le Ao o le Malo	Incumbent
Other offices
Member of the Council of Deputies
	Incumbent
	Assumed office ; 10 January 2025
O le Ao o le Malo	Tuimalealiʻifano Vaʻaletoʻa Sualauvi II
	In office; 2004 – 20 June 2007
O le Ao o le Malo	Malietoa Tanumafili II
Deputy Prime Minister of Western Samoa
	In office; 30 December 1985 – 8 April 1988
Prime Minister	Va'ai Kolone
Succeeded by	Tuila'epa Sa'ilele Malielegaoi
1st Minister of Foreign Affairs
	In office; 18 September 1982 – 31 December 1982
Preceded by	Va'ai Kolone
Succeeded by	Lauofo Meti
	In office; 24 March 1976 – 13 April 1982
Succeeded by	Va'ai Kolone
Preceded by	In office; 26 February 1988 – 2004
Constituency
Member of the Samoan Parliament
	In office; 26 February 1988 – 2004
Preceded by	Afioga Savea Sione
Succeeded by	Lufilufi Moefaauo
Constituency	Anoama'a East
	In office; 7 February 1970 – 26 February 1988
Preceded by	Taimalie Meapelo
Succeeded by	Alipia Siaosi
Constituency	Aana Alofi No. 2
	In office; May 1965 – 25 February 1967
Preceded by	Masoe Tulele
Succeeded by	Va'ai Kolone
Constituency	Vaisigano No. 1
Personal details
Born	Olaf Efi Tamasese; 1 March 1938; Motootua, Western Samoa (now Samoa)
Nationality	Samoan
Political party	Independent
Other political; affiliations	National Development Party (1988–2003); Christian Democratic Party (1985–1988)
Spouse	Masiofo Filifilia Imo Tamasese
Parents	Tupua Tamasese Meaʻole (father); Irene Gustava Noue Nelson (mother);
Alma mater	Victoria University of Wellington

Tui Ātua Tupua Tamasese Tupuola Tufuga Efi (born Olaf "Efi" Tamasese; 1 March 1938) is a Samoan paramount chief and politician. He heads one of Samoa's two royal families, the Sā Tupua (descendants of Queen Salamasina), through the family's maximal lineage title, Tupua Tamasese. He also holds the ancient pāpā title of Tui Ātua (sovereign of Atua).

Tui Ātua served as the third prime minister of Samoa from 1976 to 1982 and again later in 1982. He also served as O le Ao o le Malo (head of state of Samoa) from 2007 to 2017. As of late 2024, he was reappointed to serve on the Council of Deputies.