Banham was based in London, but lived primarily in the United States from the late 1960s until the end of his life. He studied under Anthony Blunt at the Courtauld Institute of Art, then Siegfried Giedion and Nikolaus Pevsner. Pevsner invited him to study the history of modern architecture, following his own work Pioneers of the Modern Movement (1936).The 'postmodern' was for him uneasy, and he evolved into the conscience of postwar British architecture. He broke with utopian and technical formalism.
As a professor, Banham taught at the University of London, the State University of New York (SUNY) Buffalo, and through the 1980s at the University of California, Santa Cruz. He had been appointed the Sheldon H. Solow Professor of the History of Architecture at the Institute of Fine Arts, New York University shortly before his death, but he never taught at the institution.