Alcalde (/ælˈkældi/; Spanish: [alˈkalde]), or Alcalde ordinario, is the traditional Spanish municipal magistrate, who had both judicial and administrative functions. An alcalde was, in the absence of a corregidor, the presiding officer of the Castilian cabildo (the municipal council) and judge of first instance of a town. Alcaldes were elected annually, without the right to reelection for two or three years, by the regidores (council members) of the municipal council. The office of the alcalde was signified by a staff of office, which they were to take with them when doing their business. A woman who holds the office is termed an Alcaldesa (Catalan: Alcaldessa).
Additionally, alcalde was a title given to Indian officials inside the Spanish missions, who performed a large variety of duties for the Franciscan missionaries.
In New Spain (Mexico), alcaldes mayores were chief administrators in colonial-era administrative territories termed alcaldías mayores; in colonial-era Peru the units were called corregimientos.
The office of the alcalde evolved during the Reconquista as new lands were settled by the expanding kingdoms of León and Castile. As fortified settlements in the area between the Douro and Tagus rivers became true urban centers, they gained, from their feudal lords or the kings of Leon and Castile, the right to have councils. Among the rights that these councils had was to elect a municipal judge (iudex in Latin and juez in Spanish). These judges were assisted in their duties by various assistant judges, called alcaldes, whose number depended on the number of parishes the town had. The title alcalde was borrowed from the Arabic al-qaḍi (قاضي), meaning "the judge."