The history of Samoa began when immigrants from Southeast Asia arrived in the Samoan islands approximately 3500 years ago and from there settled the rest of Polynesia, originally to the east and then north and south. There is evidence to suggest they travelled as far as South America. Contact with Europeans began in the early 1700s but did not intensify until the arrival of English missionaries and traders in the 1830s.

Halfway through the 19th century, the United Kingdom, Germany and the United States all claimed parts of the kingdom of Samoa, and established trade posts. The British withdrew their claim in 1899 and Samoa was divided between Germany and the US. The western part, Western Samoa which contains the two largest islands (the current Samoa) went to Germany, while the eastern part was allotted to the United States in 1904. The latter part is still a territory of the United States and is known as American Samoa.

From 1908, with the establishment of the Mau ("opinion") movement, Western Samoans began to assert their claim to independence.

At the outbreak of World War I, troops from New Zealand occupied the German ruled islands. In 1919 in the Treaty of Versailles, Germany dropped its claims to the islands and they were granted to New Zealand as a mandate.

New Zealand administered Western Samoa under the auspices of the League of Nations and then as a United Nations trusteeship until the country received its independence on January 1, 1962 as Western Samoa. Samoa was the first Polynesian nation to reestablish independence in the 20th century.

In July 1997 the constitution was amended to change the country's name from "Western Samoa" to "Samoa." Samoa had been known simply as Samoa in the United Nations since joining the organization in 1976. The neighboring U.S. territory of American Samoa protested the move, feeling that the change diminished its own Samoan identity. American Samoans still use the terms "Western Samoa" and "Western Samoans."

In 2002, New Zealand's prime minister Helen Clark formally apologised for two incidents during the period of New Zealand's administration: a failure to quarantine an influenza-carrying ship in 1919, leading to an epidemic which devastated the Samoan population, and the shooting of leaders of the nonviolent Mau movement during a ceremonial procession in 1926.

Samoa's rugby team has achieved some notable successes, particularly in the sevens version of the game.