Reşad Ekrem Koçu (1905–1975) was a distinguished Turkish historian and writer, best known for his encyclopedic chronicling of Istanbul’s past. Born in Istanbul and educated at Istanbul University, he served as a researcher of the Ottoman period under Ahmet Refik Altınay before transitioning to a career in education. For decades, Koçu taught history at prestigious high schools while simultaneously publishing poems, stories, and articles in numerous leading newspapers and magazines, establishing himself as a vital cultural figure in Turkey.

His magnum opus, the Istanbul Encyclopedia (İstanbul Ansiklopedisi), remains a legendary, albeit unfinished, attempt to record every aspect of the city’s history, celebrated for its colorful anecdotes and distinctive illustrations. Beyond the encyclopedia, Koçu authored significant works blending rigorous history with storytelling. His vivid depictions of Ottoman Istanbul have deeply influenced modern literature, most notably cited as a major inspiration by Nobel laureate Orhan Pamuk in Istanbul: Memories and the City.