Martha A. Sandweiss is a historian of the United States, with particular interests in the history of the American West, visual culture, and public history. She received her B. A. (magna cum laude) from Harvard University and a Ph.D. in History from Yale University. She began her career as a photography curator at the Amon Carter Museum in Ft. Worth, TX, and later taught American Studies and History at Amherst College for twenty years before joining Princeton University as Professor of History in 2009. She is currently Professor emerita.

Sandweiss is the author or editor of numerous books on American history and photography. Her newest publication is The Girl in the Middle: A Recovered History of the American West (2025). Her previous publications include Passing Strange: A Gilded Age Tale of Love and Deception across the Color Line (2009), a finalist for the Los Angeles Times Book Prize in History and the National Book Critics Circle Award in Biography, and Print the Legend: Photography and the American West (2002), winner of the Organization of American Historians’ Ray Allen Billington Award for the best book in American frontier history and the William P. Clements Award. Her other works include Laura Gilpin: An Enduring Grace (1986), winner of the George Wittenborn Award for outstanding art book; the co-edited volume The Oxford History of the American West (1994), winner of the Western Heritage Award and the Caughey Western History Association prize for the outstanding book in western history; and the co-authored book Eyewitness to History: Prints and Daguerreotypes of the Mexican War (1989). She has also written widely on the use of photographs as historical sources and contributed to books on photographers Carleton Watkins, Eliot Porter, William Garnett and Carlotta Corpron.

The founder and Director of the Princeton & Slavery Project, a collaborative public history project that explores the historical connections between the university and the institution of slavery, Sandweiss has taught a broad range of courses on the American West, narrative writing, public history, and historical archives. The recipient of grants from the National Endowment for the Humanities, the American Council of Learned Societies, and the Rockefeller Foundation, she has served on the boards of the Organization of American Historians, the American Antiquarian Society, and the Wheelwright Museum of the American Indian. She has also served as President of the Society of American Historians and the Western History Association.

She currently lives in Santa Fe, New Mexico.