Monsieur (plural: Messieurs) meant "my lord" in Middle French, and is now generally used in French as an honorific for all men (not possessing a knighthood or some higher rank), the equivalent to the English titles "Mister" and (in some senses) "Sir". Written Monsieur Dupont, M. Dupont, or less commonly Mr Dupont, the plural is messieurs (abbreviation: MM.).

Monsieur (English translation: "Mister") was the Luxembourgish entry in the Eurovision Song Contest 1989, performed in French by Park Café.