Europeans first landed on the island in either 1492 or 1502 during Spain's early exploration of the Caribbean. The Dutch, English, and French all tried to establish trading outposts on St. Lucia in the 17th century but faced opposition from hostile Caribs.

The English, with their headquarters in Barbados, and the French, centered on Martinique, found St. Lucia attractive after the sugar industry developed in 1765. Britain eventually triumphed, with France permanently ceding St. Lucia in 1815. In 1838, St. Lucia was incorporated into the British Windward Islands administration, headquartered in Barbados. This lasted until 1885, when the capital was moved to Grenada.

Increasing self-government has marked St. Lucia's 20th-century history. A 1924 constitution gave the island its first form of representative government, with a minority of elected members in the previously all-nominated legislative council. Universal adult suffrage was introduced in 1951, and elected members became a majority of the council. Ministerial government was introduced in 1956, and in 1958 St. Lucia joined the short-lived West Indies Federation, a semi-autonomous dependency of the United Kingdom. When the federation collapsed in 1962, following Jamaica's withdrawal, a smaller federation was briefly attempted. After the second failure, the United Kingdom and the six windward and leeward islands--Grenada, St. Vincent, Dominica, Antigua, St. Kitts-Nevis-Anguilla, and St. Lucia--developed a novel form of cooperation called associated statehood.

As an associated state of the United Kingdom from 1967 to 1979, St. Lucia had full responsibility for internal self-government but left its external affairs and defense responsibilities to the United Kingdom. This interim arrangement ended on February 22, 1979, when St. Lucia achieved full independence. St. Lucia continues to recognize Queen Elizabeth II as titular head of state and is an active member of the Commonwealth. The island continues to cooperate with its neighbors through the Caribbean community and common market (CARICOM), the East Caribbean Common Market (ECCM), and the Organization of Eastern Caribbean States (OECS).