Until independence in 1975, Sao Tome and Principe had few ties abroad except those that passed through Portugal. Following independence, the new government sought to expand its diplomatic relationships. A common language, tradition, and colonial experience have led to close collaboration between Sao Tome and other ex-Portuguese colonies in Africa, particularly Angola. Sao Tomean relations with other African countries in the region, such as Gabon and the Republic of the Congo, are also good. In December 2000, Sao Tome signed the African Union treaty; it was later ratified by the National Assembly.

The Sao Tomean Government has generally maintained a foreign policy based on nonalignment and cooperation with any country willing to assist in its economic development. In recent years, it has also increasingly emphasized ties to the United States and western Europe. It maintains relations with the Republic of China (Taiwan) instead of the People's Republic of China.