Banjul, officially the City of Banjul, is the capital of The Gambia. It is the centre of the eponymous administrative division which is home to an estimated 400,000 residents, making it The Gambia's largest and most densely populated metropolitan area. Banjul is located on St Mary's Island, where the Gambia River enters the Atlantic Ocean.

The Gambia, officially the Republic of the Gambia, is a country in West Africa. Geographically, The Gambia is the smallest country in continental Africa; it is surrounded by Senegal, except for its western coast on the Atlantic Ocean. It is situated on both sides of the lower reaches of the Gambia River, which flows through the centre of the country and empties into the Atlantic Ocean. The national namesake river demarcates the elongated shape of the country, which has an area of 11,300 square kilometres (4,400 sq mi) and a population of 2,468,569 people in 2024. The capital city is Banjul, which has the most extensive metropolitan area in the country; the second- and third-largest cities are Serekunda and Brikama.