César Denis Daly (17 July 1811, Verdun[1] – 11 January 1894, Wissous)[2] was a French architect, publisher, and writer.

A precursor to Viollet-le-Duc, César Daly worked as a diocesan architect from 1843 to 1877, principally on the restoration of the Cathedral of Sainte-Cécile in Albi.

A supporter of the communal living embodied by the phalanastère and the socioeconomic theories of Charles Fourier, he founded in 1848 the ephemeral Société d'artistes décorateurs et industriels, and the same year, during the upheaval of the French Second Republic, stood as a candidate for the National Constituent Assembly.

Daly was named to the Légion d'honneur on 13 August 1861 and received the RIBA's Royal Gold Medal in 1892.

More than a practitioner on the ground, César Daly was also influential through his activities in associations and the publishing world of architecture.