The USNO-B1.0 Catalogue presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for 1,045,175,762 objects derived from 3,648,832,040 separate observations. The data were taken from scans of 7,435 Schmidt plates taken from various sky surveys during the last 50 years. The catalogue is expected to be complete down to V=21; the estimated accuracies are 0.2arcsec for the positions at J2000, 0.3mag in up to 5 colors, and 85% accuracy for distinguishing stars from non-stellar objects