structural:expansion
Independence

After repeated efforts by the Samoan independence movement, the New Zealand Western Samoa Act of 24 November 1961 terminated the Trusteeship Agreement and granted the country independence as the Independent State of Western Samoa, effective 1 January 1962. Western Samoa, the first small-island country in the Pacific to become independent, signed a Treaty of Friendship with New Zealand later in 1962. Western Samoa joined the Commonwealth of Nations on 28 August 1970. While independence was achieved at the beginning of January, Samoa annually celebrates 1 June as its independence day.

At the time of independence, Fiamē Mataʻafa Faumuina Mulinuʻu II, one of the four highest-ranking paramount chiefs in the country, became Samoa's first prime minister. Another paramount chief, Tuiaana Tuimalealiʻifano Suatipatipa II, was admitted to the Council of Deputies; the remaining two – Tupua Tamasese Meaʻole and Malietoa Tanumafili II – became joint heads of state for life.

On 15 December 1976, Western Samoa was admitted to the United Nations as the 147th member state. It asked to be referred to in the United Nations as the Independent State of Samoa.

Travel writer Paul Theroux noted marked differences between the societies in Western Samoa and American Samoa in 1992.

On 4 July 1997 the government amended the constitution to change the name of the country from Western Samoa to Samoa, the name it had been called by in the United Nations since it joined. American Samoa protested against the name change, asserting that it diminished its own identity.

In 2002, New Zealand prime minister Helen Clark formally apologised for New Zealand's role in the Spanish influenza outbreak in 1918 that killed over a quarter of Samoa's population and for the Black Saturday killings in 1929.

On 7 September 2009, the government changed the rule of the road from right to left, in common with most other Commonwealth countries - most notably countries in the region such as Australia and New Zealand, home to large numbers of Samoans. This made Samoa the first country in the 21st century to switch to driving on the left.

At the end of December 2011, Samoa changed its time zone offset from UTC−11 to UTC+13, effectively jumping forward by one day, omitting Friday, 30 December from the local calendar. This also had the effect of changing the shape of the International Date Line, moving it to the east of the territory. This change aimed to help the nation boost its economy in doing business with Australia and New Zealand. Before this change, Samoa was 21 hours behind Sydney, but the change means it is now three hours ahead. The previous time zone, implemented on 4 July 1892, operated in line with American traders based in California. In October 2021, Samoa ceased daylight saving time.

In 2017, Samoa signed the UN treaty on the Prohibition of Nuclear Weapons.

In June 2017, Parliament amended Article 1 of the Samoan Constitution to make Christianity the state religion.

In September 2019, a measles outbreak resulted in the deaths of 83 people. Following the outbreak, the government imposed a curfew in December later during the same year.

In May 2021, Fiamē Naomi Mataʻafa became Samoa's first female prime minister. Mataʻafa's FAST party narrowly won the election, ending the rule of long-term Prime Minister Tuilaʻepa Saʻilele Malielegaoi of the Human Rights Protection Party (HRPP), although the constitutional crisis complicated and delayed this. On 24 May 2021, she was sworn in as the new prime minister, though it was not until July that the Supreme Court ruled that her swearing-in was legal, thus ending the constitutional crisis and bringing an end to Tuilaʻepa's 22-year premiership. The FAST party's success in the 2021 election and subsequent court rulings also ended nearly four decades of HRPP rule.