Jacob Zuma's tenure as South Africa's fourth post-apartheid president began on 9 May 2009 and ended on 14 February 2018. He held office under a mandate from the parliamentary caucus of the African National Congress (ANC), which had governed South Africa since 1994 and which won comfortable majorities in the 2009 and 2014 national elections. His presidency was beset by controversy, and he faced, and defeated, an impeachment attempt and a record eight motions of no confidence in the South African Parliament, four of which went to a vote. His party asked him to resign in February 2018, ahead of the constitutional end of his second term.

Zuma's administration launched the R4-trillion National Infrastructure Plan and signed a controversial nuclear power deal with the Russian government, blocked by the Western Cape High Court in 2017. The administration was praised for its progressive HIV/AIDS policy. As president, Zuma increasingly relied on left-wing populist rhetoric, and in his 2017 State of the Nation address announced a new policy of "radical economic transformation". Few of the attendant policy initiatives were implemented before the end of his presidency, but they included land expropriation without compensation, free higher education, and a series of attempted structural reforms in key sectors, involving restrictions on foreign ownership and more stringent black economic empowerment requirements.

In the international arena, Zuma emphasised South-South solidarity and economic diplomacy. The admission of South Africa to the BRICS grouping has been described as a major triumph for him. During South Africa's tenure on the United Nations Security Council in 2011–2012, the administration was criticised for vacillating in its stance on foreign military intervention in the Libyan and Syrian civil wars. In 2015, the South African government hosted Sudanese President Omar al-Bashir in Johannesburg while he was a fugitive from the International Criminal Court (ICC), and, when it was reprimanded for doing so, announced its intention to withdraw from the Rome Statute and the ICC.

During Zuma's second term, his administration was increasingly preoccupied by domestic controversy. In 2014, the Public Protector found that Zuma had improperly benefited from state expenditure on upgrades to his Nkandla homestead, and in 2016 the Constitutional Court ruled that Zuma had thereby failed to uphold the Constitution, leading to calls for his resignation and a failed impeachment attempt in the National Assembly. By early 2016, there were also widespread allegations – investigated by the Zondo Commission between 2018 and 2021 – that the Gupta family had acquired immense and corrupt influence over Zuma's administration, amounting to state capture. In February 2018, the National Executive Committee of the ANC recalled Zuma, threatening to support a motion of no confidence in him if he did not resign. He resigned on 14 February and was replaced by his deputy president, Cyril Ramaphosa.

Former Deputy President Jacob Zuma became the presumptive presidential candidate of South Africa's ruling African National Congress (ANC) in December 2007, when he was elected ANC president at the party's 52nd National Conference. Kgalema Motlanthe became president after President Thabo Mbeki's resignation in 2008, but was widely understood to be leading a de facto caretaker administration ahead of the 22 April 2009 general election. In the run-up to the election, the ANC campaigned under the theme "Continuity and Change", and it won the national vote with a slightly diminished majority of 65.90%. On 6 May, Zuma was indirectly elected the President of South Africa in a vote of the National Assembly, and he was sworn in on 9 May.

The ANC retained its majority in the 2014 national election, and on 21 May 2014 the National Assembly elected Zuma to a second term as president.

Zuma was criticised for a lack of stability in his cabinet – during his two terms in office, he implemented twelve cabinet reshuffles , and some of his appointments unsettled financial markets. His deputy president was Cyril Ramaphosa, who was also the deputy president of the ANC.

In August 2009, Zuma nominated Sandile Ngcobo as Chief Justice of South Africa. In two joint statements, opposition parties the Democratic Alliance (DA), the Congress of the People (COPE), the Independent Democrats and the Inkatha Freedom Party criticised Zuma, claiming that he had not fulfilled the constitutional requirement of consulting the opposition before making a decision. They also expressed support for Dikgang Moseneke, the Deputy Chief Justice and formerly the favourite for the Chief Justice post. Ngcobo's appointment was confirmed in October 2009.