Peter Reyner Banham, FRIBA (2 March 1922 – 19 March 1988) was an English architectural critic and prolific writer best known for his theoretical treatise Theory and Design in the First Machine Age (1960) and for his 1971 book Los Angeles: The Architecture of Four Ecologies. In the latter he categorized the Los Angeles experience into four ecological models (Surfurbia, Foothills, The Plains of Id, and Autopia) and explored the distinct architectural cultures of each ecology.