Hans Sedlmayr (born 18 January 1896 in Hornstein (Burgenland) – died 9 July 1984 in Salzburg) was an Austrian art historian. Sedlmayr was University Professor of Art History in Vienna from 1936 until 1945, then in Munich from 1951 until 1964, and finally at the University of Salzburg from 1965-69, where he established the art history curriculum. He specialized in the study of Baroque architecture and wrote a book on the churches of Francesco Borromini. A founding member of the New Vienna School of art history, which based itself on the writings of Alois Riegl, he wrote a manifesto in 1931 called Zu einer strengen Kunstwissenschaft ("Toward a Rigorous Study of Art"). He is the author of Verlust der Mitte: Die bildende Kunst des 19. und 20. Jahrhunderts als Symptom und Symbol der Zeit (1948, "Loss of the Center: the Fine Arts of the Nineteenth and Twentieth Centuries as Symptom and Symbol of the Times"), published in English in 1957 as Art in Crisis: The Lost Center.

He joined the National Socialist German Workers Party (NSDAP) in 1932 and following World War II he lost his position at the Technische Hochschule in Vienna as a result of his membership. He moved to Bavaria, joining the editorial staff of a Catholic magazine, Wort und Wahrheit ("Word and Truth"), from 1946 to 1954. In 1951 he became a professor at the Ludwig Maximilians University of Munich.

The history of art from the early nineteenth century onward is commonly viewed as a succession of conflicts between innovatory and established styles that culminated in the formalism and aesthetic autonomy of high modernism. In "Art and Crisis", first published in 1948, Hans Sedlmayr argues that the aesthetic disjunctures of modern art signify more than matters of style and point to much deeper processes of cultural and religious disintegration. As Roger Kimball observes in his informative new introduction, "Art in Crisis" is as much an exercise in cultural or spiritual analysis as it is a work of art history. Sedlmayr's reads the art of the last two centuries as a fever chart of the modern age in its greatness and its decay. He discusses the advent of Romanticism with its freeing of the imagination as a conscious sundering of art from humanist and religious traditions with the aesthetic treated as a category independent of human need.Looking at the social purposes of architecture, Sedlmayr shows how the landscape garden, the architectural monument, and the industrial exhibition testified to a new relationship not only between man and his handiwork but also between man and the forces that transcend him. In these institutions man deifies his inventive powers with which he hopes to master and supersede nature. Likewise, the art museum denies transcendence through a cultural leveling in which "Heracles and Christ become brothers" as objects of aesthetic contemplation. At the center of "Art in Crisis" is the insight that, in art as in life, the pursuit of unqualified autonomy is in the end a prescription for disaster, aesthetic as well as existential. Sedlmayr writes as an Augustinian Catholic. For him, the underlying motive for the pursuit of autonomy is pride. The "lost center" of his subtitle is God. The dream of autonomy, Sedlmayr argues, is for finite, mortal creatures, a dangerous illusion. The book invites serious analysis from art critics and theological thinkers alike. Hans Sedlmayr (1896-1984) was a founding member of the New Vienna School of art historians.His books include "The Architecture of Borromini", "The Revolution of Modern Art", and "Austrian Baroque Architecture."