The French took possession of Saint Lucia in 1635, but it changed hands frequently between France and Great Britain. In 1814, France finally ceded the island to Great Britain. During the colonial period, Saint Lucia did not have its own unique flag. In 1939, the British gave the island its own coat of arms. The coat of arms consisted of a black shield with two bamboo sticks forming a cross. The four squares of the shield were filled with two roses symbolizing England and two fleur-de-lis symbolizing France. This emblem was used on the island's flag.

From 1958 to 1962, Saint Lucia was a member of the West Indies Federation, but this union was unsuccessful, and the island became an associated state. This gave the territory full control over internal affairs, but left foreign policy and defense under the responsibility of Britain. On the same day that Saint Lucia became an associate state, a new flag designed by a local artist was adopted. When the island eventually became an independent state on February 22, 1979, the design of the flag remained unchanged, but some changes were made to the shade of blue and the size of the triangles. The last modification of the flag took place on February 22, 2002, when the shade of blue was changed again, so the modern flag of Saint Lucia has a light blue base. However, the design of the flag was developed on March 1, 1967, and its base with minor changes has survived to this day.