John P. Coolidge (December 16, 1913 - July 31, 1995) was an architectural historian at Harvard and Director of the Fogg Art Museum.

In 1940, he participated in the founding of the Society of Architectural Historians, initiated by Kenneth Conant, and was its first vice president. In 1942 Coolidge published the research for his master's degree in a unique examination of a factory town-architecture, both industrial and residential, "Mill and Mansion: a Study of Architecture and Society in Lowell, Massachusetts." The book was such a strong social history that Columbia University Press published it in their series "Studies in American Culture." Coolidge's dissertation topic was on Giacomo Barozzi, Il Vignola. A seminal article on Vignola and the architect's contribution to the Villa Giulia and St. Peters, appeared in 1943. His dissertation was nearly complete when he joined the U. S. Navy during World War II, initially as an ensign. He was posted in communications in Washington, DC, and London. He was discharged in 1946, taught at the University of Pennsylvania until his dissertation was accepted in 1947. He was appointed an Assistant Professor in the department of Fine Arts at Harvard in 1947 and in the following year was named Associate Professor and director of Harvard's Art Museums. As director of the Fogg Art Museum, he built the art collections, particularly in Islamic and modern. The same year, 1948, he was named a trustee of the Museum of Fine Arts, Boston. In 1955 he was promoted to full professor. Coolidge continued the Fogg's tradition of the museum as a laboratory for curatorial studies, begun under Paul J. Sachs (q.v.). He retired from the Fogg as William Dorr Boardman Professor of Fine Arts, Emeritus, in 1972, presiding as president of the MFA, Boston, 1973-1975. In his later years, Coolidge tackled art museum architecture, Patrons and Architects, again, examining how buildings affect the environment for which they exist in his 1989 book. An art history, "Gustave Doré's London", appeared in 1992.The John Coolidge Objects Laboratory at the Harvard Museums is named in his memory. As a museum director, Coolidge notably added the first modernist works to the Fogg, including the first Morris Louis.