The 2015 Spanish regional elections were held on Sunday, 24 May 2015, to elect the regional parliaments of thirteen of the seventeen autonomous communities—Aragon, Asturias, the Balearic Islands, the Canary Islands, Cantabria, Castile and León, Castilla–La Mancha, Extremadura, La Rioja, Madrid, Murcia, Navarre and the Valencian Community—, not including Andalusia, the Basque Country, Catalonia and Galicia, which had separate electoral cycles.

The ruling People's Party (PP) suffered one of the harshest loss of votes for any party in the quadrennial regional elections, losing all of its absolute majorities and most of the regional administrations at stake, including notable PP strongholds such as the Valencian Community which it had held continuously since 1995.

The Spanish Socialist Workers' Party (PSOE) was unable to capitalize on the PP backlash and kept losing votes from 2011.

Determination of election day varied depending on the autonomous community, with each one having competency to establish its own regulations.

In other cases—namely, Aragon, the Balearic Islands, Castile and León, Extremadura, Navarre and the Valencian Community—, the law granted presidents the power to call a snap election resulting in a fresh four year-parliamentary term.