In many countries, a mayor (/ˈmɛər/ or /ˈmeɪər/, from the Latin maior [majˈjɔr], meaning "bigger") is the highest-ranking official in a municipal government such as that of a city or a town.

Worldwide, there is a wide variance in local laws and customs regarding the powers and responsibilities of a mayor, as well as the means by which a mayor is elected or otherwise mandated. Depending on the system chosen, a mayor may be the chief executive officer of the municipal government, may simply chair a multi-member governing body with little or no independent power, or may play a solely ceremonial role. Options for selection of a mayor include direct election by the public, or selection by an elected governing council or board.