Porto-Novo, population 179,138 (1992), is the official capital of Benin. It is a port on Porto-Novo Lagoon, an arm of the Gulf of Guinea. Porto-Novo is Benin's second largest city, but it is less important commercially and industrially than Cotonou. The city is the center of an agricultural region whose chief product is palm oil. It also exports cotton and kapok.

Porto-Novo was probably founded in the late 16th century by the Gun people. It got its name from the Portuguese, meaning "New Port", who built a trading post there in the 17th century in order to ship African slaves to the Americas. The Kingdom of Porto-Novo accepted French "protection" in 1863 in order to fend off British encroachment. However, the neighboring Kingdom of Abomey resented the French presence, and war broke out. In 1883 the French navy landed at Porto-Novo and Cotonou, and Porto-Novo was incorporated into the French colony of Dahomey. In 1900 it was made Dahomey's capital.

Features of the city include the Institute of Higher Studies of Benin, the Porto Novo Museum of Ethnography and King Toffa's palace.