John Brewer's research interests have focused on two areas: issues of value in the visual-art world and questions of travel, tourism, identity, and place.

He has had a long-standing interest in the fraught relationship between culture and money, on which he has written extensively during his career. Starting with the assumption that the art world is dominated by a shared struggle over value, ownership, and the meaning of art, Brewer examines questions such as: What makes a work of art great? What makes it valuable? Is it genuine or a fake? To whom does it belong—an individual owner, a culture, a nation, or humanity? Artists, scholars, curators, patrons, collectors, dealers, and even the public have their own answers to these questions. Brewer has studied these debates and their participants over the last five centuries.

Part of this project appeared as The American Leonardo: A Tale of Obsession, Art, and Money (Oxford University Press, 2009), but he continued to pursue this topic through an investigation of the place of curators in fine-art museums and their complex relations with art scientists and conservators, as well as their struggle to retain their integrity in a world increasingly dominated by market forces.

Brewer's second project examines travel, tourism, and identity in the eighteenth and nineteenth centuries, a time when the terms "tourism" and "tourist" first came into common use. He asks: What was the nature and purpose of tourism, how did tourists affect the identity and economy of the places they visited, and how have relations between travelers and natives changed in a world increasingly characterized by high levels of mobility? He also wrote a major case study of the Bay of Naples, Vesuvius, and Pompeii in the nineteenth century.

Brewer has previously held faculty positions at the University of Chicago, European University Institute in Florence, UCLA, Harvard University, Yale University, and Cambridge University. He has also been a visiting professor at Washington University in St. Louis and a research fellow at Cambridge University. In 2011, he was a visiting professor at Ecole des Hautes Etudes en Science Sociale in Paris and a visiting research associate at Herzog August Bibliothek in Wolfenbüttel, Germany. In 2010 he was a visiting fellow at the University of Munich, and in 2009 he was a Ford Lecturer at the University of Oxford. He was a Moore Distinguished Visitor at Caltech in 2001. His book The Pleasures of the Imagination: English Culture in the Eighteenth Century (Farrar, Straus and Giroux, 1997) was a National Book Critics Circle Award nominee in criticism and won the Wolfson History Prize in 1998.