Karl Moser (10 August 1860 – 28 February 1936) was an architect from Switzerland.
In 1928 he was president of the newly founded Congrès International d'Architecture Moderne, an organisation, steered prominently by the pioneers of modernism, architects Le Corbusier and Walter Gropius, which championed rational and functionalist architecture, while critiquing the type of revivalist architecture typified by Moser's own work.
Indeed, it was at this time that Moser's own work changed radically towards modernism, exemplified in the St. Anthony's (Antoniuskirche) in Basel (1925–27), built in reinforced concrete rather than brick and stone typical for his earlier works.
His son Werner M. Moser also became a notable architect.
This article about a Swiss architect is a stub.