Mayenne (majɛn) is a department in northwest France named after the Mayenne River.
Mayenne is one of the original 83 departments created during the French Revolution on March 4, 1790. It constitutes the western part of the former province of Maine.
Mayenne is part of the current region of Pays de la Loire and is surrounded by the departments of Manche, Orne, Sarthe, Maine-et-Loire, and Ille-et-Vilaine.
The inhabitants of the department are called Mayennais. This demonym is not the source of the word mayonnaise.