Formerly a British colony and protectorate, the country has been independent since 27 April 1961 within the Commonwealth; on 19 April 1971 Sierra Leone proclaimed itself a Republic. The government, formed by the People’s Congress (APC), kept a firm grip on the leadership of the country until 1992, when Valentine Strasser came to power after a coup d’état. Guerrilla warfare ensued, led by the Revolutionary United Front (RUF). Civil war only came to a conclusion in 2001, with the intervention of UN peace forces which stayed in the country until 2005. On the basis of the 1991 Constitution, executive power is in the hands of the President of the Republic, elected by direct suffrage for five years; the office of Prime Minister, reinstated in 2018, has coordination functions. Legislative power is exercised by a House of Representatives of 146 members, including 132 directly elected and 14 local chiefs for five-year term.

The main crops are cassava and rice; other crops include millet, maize and sweet potatoes; commercial crops include cocoa, coffee, peanuts and oil palm. Forests and ocean fishing are important activities (molluscs and shellfish).
Iron ore (in Lunsar and Koinadugu-Farangbaya) and diamond production (in the Kono, Kenema and Bo districts) is also considerable. The country is rich in rutile and ilmenite (in Bonthe), gold (at Baomahun, Komahun), bauxite (in the Mokanji Hills, in Kambia and at Port Loko).
Considerable hydrocarbon reserves are located offshore, the mining of which is managed by foreign companies. The oil extraction operations, mostly managed by foreign companies that also carry out prospecting in extensive offshore reserves, has fuelled strong economic growth since 2012. The main industries are those involved in the processing of agricultural and forest products. An oil refinery and a cement factory are active in Freetown. There is still a serious lack of infrastructure.