Local government in Spain refers to the government and administrative powers exercised by what the Constitution calls "local entities", principally municipalities, but there are also various forms of supra-municipal bodies such as provincial councils and cabildos and sub-municipal bodies such as comarcas. Together, these local entities make up the third tier of government, the first tier being the state (Spain) and the second tier the regions (autonomous communities). Spain adheres to the European Charter of Local Self-Government although it declares itself not bound to the full extent by the requirement for direct elections of all local authorities. 
The governing and administrative body of the non-insular provinces is the diputación provincial ("provincial council"). However when there is only one province in an autonomous community, the functions of the diputacion are replaced by the regional government. It is formed by a plenary council, the deliberative body, and an executive committee formed by the president and part of the deputies. The provincial councillors are indirectly elected to a 4-year mandate by the municipal councils as function of the results of the municipal elections. The Spanish Constitution guarantees the autonomy of the provinces.
A Cabildo is the governing body used for each of the seven major islands of the Canarian Archipielago, with similar functions to a provincial council.
The collective body for most of the municipalities is the Ayuntamiento. The main organ of the Ayuntamiento is the plenary, the deliberative body formed by the elected councillors, and presided by the alcalde ("Mayor"). Unlike in other European countries the Mayor is not directly elected. He is invested by the councillors. If no head of list of each electoral list commands an absolute majority of the votes of the councillors in the Plenary, the head of list of the most voted list becomes Mayor. The executive organs are the Mayor, the tenientes de alcalde ("deputy mayors") and the executive committee formed by a number of the elected councillors (Junta or Consejo de Gobierno). While the Plenary retains the vote of censure to remove the Mayor, the system confers much power to the Mayor, thus the Mayoral competences and authority have become a main point of discussion about the Spanish local government. The Spanish Constitution guarantees the autonomy of the municipalities.
- Concejo abierto
The concejo abierto ("open council") is the assembly system used for the government and administration of low-population municipalities. The government is exercised by the Mayor and the asamblea vecinal ("neighed assembly"), formed by all the electors of the municipality.
Other local entities
Other entities belonging to the local tier, sharing the feature of not being mentioned in the Constitution, and thus, the name and its simple existence being highly dependent on the particular regional legislation are:
- Entidad de Ámbito Territorial Inferior al Municipio (EATIM). Administrative unit below the municipal level.
- Mancomunidad (association of municipalities)
- Metropolitan area
- Moreno, Angel M. (June 2016). Merloni, Francesco (ed.). Regionalisation Trends in European Countries 2007-2015: Spain. Congress of Local and Regional Authorities of The Council of Europe. pp. 183–191.
- Cools & Verbeek 2013, Recommendation 336 (2013) paragraph 2(b).
- Cools & Verbeek 2013.
- Canel 1994, pp. 51–52.
- Canel 1994, pp. 48–49.
- "Electoral Systems and Voting Procedures at Local Level". Local and regional authorities in Europe. Council of Europe (68): 35. ISBN 9287139830.
- Canel 1994, p. 49.
- Canel, María José (1994). "Local government in the Spanish autonomic state". Local Government Studies. 20 (1): 44–59. doi:10.1080/03003939408433710.CS1 maint: ref=harv (link)
- Cools, Marc; Verbeek, Leen (19–21 March 2013). Local and regional democracy in Spain. Council of Europe.CS1 maint: ref=harv (link)