Lagos State (Yoruba: Ìpínlẹ̀ Èkó, Gun: Ayìmátẹ̀n Awọnlìn tọ̀n) is a state in southwestern Nigeria. Of the 36 states, Lagos is the most populous state but has the smallest landmass in Nigeria. Bounded to the south by the Bight of Benin and to the west by the international border with the Republic of Benin, Lagos State borders Ogun State to the north and east, making it the only Nigerian state to border only one other state. Named for the city of Lagos — the most populous city in Africa — the state was formed from the Western Region and the former Federal Capital Territory on 27 May 1967.
Geographically, Lagos State is dominated by bodies of water with nearly a quarter of the state's area being lagoons, creeks, and rivers. The largest of these bodies are the Lagos and Lekki lagoons in the state's interior with the Ogun and Osun rivers flowing into them. Many other rivers and creeks flow throughout the state and serve as vital means of transportation for people and goods. On land, non-urbanized areas are within the tropical Nigerian lowland forests ecoregion with natural areas containing threatened populations of mona monkey, tree pangolin, and hooded vulture along with a transitory population of African forest elephants. Offshore, the state is also biodiverse as there are large fish populations along with African manatees and crocodiles.