Sigfried Giedion (14 April 1888, Prague – 10 April 1968, Zürich) (also spelled Siegfried Giedion) was a Bohemia-born Swiss historian and critic of architecture.
His ideas and books, Space Time and Architecture, and Mechanization Takes Command, had an important conceptual influence on the members of the Independent Group at the Institute of Contemporary Arts in the 1950s era.
He was the first secretary-general of the Congrès International d'Architecture Moderne. He has also taught at the Massachusetts Institute of Technology and Harvard University.
He was a pupil of Heinrich Wölfflin.
Space, Time & Architecture Giedion wrote an influential standard history of modern architecture, Mechanization Takes Command established a new kind of historiography.
He married Carola Giedion-Welcker, who created a circle of vanguardist artists in Switzerland, which included architect Aldo van Eyck. His daughter Verena married the architect Paffard Keatinge-Clay.