What is the only official language of Monaco?

The only official language of Monaco is French.

French became dominant as Monaco’s administrative language during the 19th century, when the principality’s ties with neighboring France deepened. The Treaty of Turin in 1860 transferred the surrounding County of Nice to France, and Italian—once used officially in Monaco—was replaced by French. Monaco’s Constitution identifies French as the official language.

That does not mean French is the only language heard in daily life. Monégasque, a traditional variety of Ligurian, is Monaco’s heritage or national language and appears on some street signs. It has also been taught in schools, including as a compulsory subject for younger pupils. Italian is common because of Monaco’s large Italian community, while English is widely used in international business and tourism.

A frequent mix-up is to name Monégasque because it is Monaco’s distinctive local tongue. It is culturally important, but it is not the principality’s official language; that status belongs solely to French.