The National Geographic Society-Palomar Observatory Sky Atlas contains photographic reproductions of red- and blue-sensitive photographs of fields obtained with the 48-inch Schmidt telescope of the Palomar Observatory for the National Geographic Society-Palomar Observatory Sky Survey. The atlas covers the entire sky north of -27° declination. The sky survey was made financially possible by generous grants from the National Geographic Society. The Society provided the photographic materials and equipment required, the salaries of the personnel employed full or part time on the survey, and in addition, the production of two contact positives on glass of each survey photograph. One set of these positives was used to print the reproductions for the sky atlas. The observing time with the 48-inch Schmidt telescope required to obtain the sky survey photographs was made available by the Palomar Observatory of the California Institute of Technology. The copyright for the Atlas is held by the National Geographic Society. Permission to reproduce prints or any part of them should be requested: for scientific publications from the Director of the Mount Wilson and Palomar Observatories, for general publications from the National Geographic Society.