The Varieties of Religious Experience: A Study in Human Nature is a book by Harvard University psychologist and philosopher William James. It comprises his edited Gifford Lectures on natural theology, which were delivered at the University of Edinburgh in Scotland in 1901 and 1902. The lectures concerned the nature of religion and the neglect of science in the academic study of religion.

William James was an American philosopher and psychologist, and the first educator to offer a psychology course in the United States. James was one of the leading thinkers of the late nineteenth century and is believed by many to be one of the most influential philosophers the United States has ever produced, while others have labeled him the "Father of American psychology".