A referendum on political reform was held in Spain on Wednesday, 15 December 1976, to gauge support for either the ratification or repealing of the Political Reform Act which had been approved by the Cortes Españolas on 18 November 1976.

(Spanish: ¿Aprueba el Proyecto de Ley para la Reforma Política?).

Its aim was to move away from the dictatorship of the Franco era and turn Spain into a constitutional monarchy with a parliament system based on representative democracy.

The law provided for the legalisation of political parties and a democratic election to Constituent Cortes, a committee of which then drafted the Constitution.

The highest percentage figure in each polling survey is displayed with its background shaded in the leading choice's colour.