Throughout history people have looked at the world around them and wondered about its shape. Ancient Greek philosophers, scholars and learned people debated the question before coming to the consensus that the Earth was a sphere. Using measurements of shadows at noon on the summer solstice, and geometry, the polymath Eratosthenes even managed to calculate a circumference for the earth of some 250,000 stadia, or 29,000 miles. Even as the belief in a spherical Earth became widespread, however, people continued to wonder, could there really be a far side? Wouldn't everything be upside down? In 1522, the return of Ferdinand Magellan's expedition seemed to conclusively demonstrate the globular nature of the earth. Nevertheless, based on scripture and their own observations, some people continued, and continue to this day, to argue that the Earth is a flat disk, centered on the North Pole and enclosed by a wall of ice.

In May of 1998, Science, Technology and Business Division Reference Librarian, Ruth S. Freitag, published a list of references covering the flat earth theory and its advocates. Freitag's guide incorporated journal and magazine articles, books, book chapters, and even book excerpts into a single list of references, and included a number of resources from outside the Library of Congress. This guide is a continuation of that original list, adding links to the catalog and online versions where available. Books, book chapters, and book excerpts have been split into a separate list from journal and magazine articles for ease of use. This guide introduces more recently produced materials while preserving the content of Freitag's original work.