Impact craters have been used as a standard metric for a plethora of planetary applications for many decades, including age-dating, geologic mapping and stratigraphic relationships, as tracers for surface processes, and as locations for sampling lower crust and upper mantle material. Utilizing craters for these and other investigations is significantly aided by a uniform catalog of craters across the surface of interest. Consequently, catalogs of craters have been developed for decades for the Moon and other planets. We present a new global catalog of Martian craters statistically complete to diameters D >= 1 km. It contains 384,343 craters, and for each crater it lists detailed positional, interior morphologic, ejecta morphologic and morphometric data, and modification state information if it could be determined. In this paper, we detail how the database was created, the different fields assigned, and statistical uncertainties and checks. In our companion paper (Robbins and Hynek, 2012), we discuss the first broad science applications and results of this work.