Dr. Spiro Konstantine Kostof (7 May 1936 - 7 December 1991) was a leading architectural historian and inspirational teacher at the University of California, Berkeley. His books continue to be widely read and some are routinely used in collegiate courses on architectural history.

A native of Turkey, Kostof was educated at Istanbul's Robert College. He came the United States in 1957 for graduate work at Yale University. Although he intended to major in drama, his interests shifted to architectural history. He received his Ph.D. in 1961, then taught at Yale for four years, before moving to the University of California to join the faculty of the College of Environmental Design. He was to remain at Berkeley for the duration of his career.

Kostof's approach to architectural history emphasized urbanism as well as architecture and showed how architectural works are embedded in their physical and social contexts. Commonly accepted today, Kostof's approach was a break with previous directions in architectural history which tended to emphasize the sequence of styles and to study architectural works in relative isolation from their settings. Kostof's textbook, A History of Architecture: Settings and Rituals (1985) embodied these ideas and soon became one of the standard texts in the field.

In 1987, Kostof hosted a five-part PBS series, America by Design.

Kostof's publications were wide-ranging and included The Architect: Chapters in the History of the Profession, The City Shaped: Urban Patterns and Meanings Through History, America by Design, and The City Assembled: Elements of Urban Form through History.

In 1993, following his death, the Society of Architectural Historians established the "Spiro Kostof Award," to recognize books "in the spirit of Kostof's writings," particularly those that are interdisciplinary and whose content focuses on urban development, the history of urban form, and/or the architecture of the built environment.