Robert Anthony Orsi (born 1953) is a scholar of American history and Catholic studies. 
Orsi was born and raised in the Bronx borough of New York City. He majored in religion and sociology at Trinity College (CT) and graduated salutatorian in 1975, receiving both a Danforth and Watson Scholarship. He attended graduate school in religion at Yale University where his prize-winning dissertation formed the basis of his first book, The Madonna of 115th Street. He taught at Fordham University at Lincoln Center from 1981 to 1988, at Indiana University from 1988 to 2001, and Harvard University/Harvard Divinity School from 2001 to 2007. He currently teaches at Northwestern University.
He is currently at work on The Cambridge Companion to Religious Studies and on a social and cultural history of 20th-century Catholic childhoods in the United States, to be published by Harvard University Press.
- 2000 Guggenheim Fellowship 
- 1999 National Endowment for the Humanities Fellowship 
- Fulbright Fellowship
- John Gilmary Shea Prize from the American Catholic Historical Association, for The Madonna of 115th Street
- Jesuit National Book Award, for The Madonna of 115th Street
- Merle Curti Award in American Social History from the Organization of American Historians, for Thank You, Saint Jude
- Award for Excellence in the Study of Religion from the American Academy of Religion, for Between Heaven and Earth
- "When 2+2=5", The American Scholar, Spring 2007
- Between Heaven and Earth: The Religious Worlds People Make and the Scholars Who Study Them. Princeton University Press. 2005. ISBN 978-0-691-04903-8.
- The Madonna of 115th Street: Faith and Community in Italian Harlem, 1880-1950. Yale University Press. 2002. ISBN 978-0-300-09135-9. (1st edition 1985),
- Thank You, Saint Jude: Women’s Devotion to the Patron Saint of Hopeless Causes. Yale University Press. 1998. ISBN 978-0-300-07659-2.
- Robert A. Orsi, ed. (1999). Gods of the City: Religion and the American Urban Landscape. Indiana University Press. ISBN 978-0-253-21276-4.
- Melissa R. Katz, Robert A. Orsi, eds. (2001). Divine mirrors: the Virgin Mary in the visual arts. Oxford University Press. ISBN 978-0-19-514557-1.