An all-sky catalog of Galactic OB stars has been created by extending the Case-Hamburg Galactic Plane Luminous Stars surveys to include 5,500 additional objects drawn from the literature. This work brings the total number of known or reasonably suspected OB stars to over 16,000. This catalog contains UBV photometry and MK spectral type classifications for these objects as well as radial velocities. This project originated in the summer of 1991 when the author began compiling a cross-reference catalog and tabulation of published UBVbeta photometry for stars listed in Stephenson and Sanduleak's Luminous Stars (LS) in the Southern Milky Way Catalog (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/III/43">CDS Cat. III/43</a>). This database was published in July 1993 (Reed 1993, ApJS, 87, 367) and was subsequently expanded to include compilations of published MK classifications (Reed & Beatty 1995, ApJS, 97, 189), 4-color photometry (Read 1996, A&AS, 117, 313), and radial velocities (Reed & Kuhna 1997, AJ, 113, 823) for these objects. In mid-1997 the project was again expanded to include UBVbeta photometry for stars listed in the Northern-hemisphere volumes of the "Case-Hamburg" (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/III/76">CDS Cat. III/76</a>) surveys (Reed 1998, ApJS, 115, 271); MK classifications for the Northern stars were similarly compiled and made electronically available to interested parties, though they were not formally published. Most of the LS objects are OB stars, but there are as well a number of A, F, and G supergiants and a few white dwarfs and Wolf Rayet stars. These surveys reached a limiting photographic magnitude of ~13.5, and were based on objective-prism surveys of dispersion 580 Angstrom/mm at H-gamma. OB stars is here taken to mean main-sequence stars down to temperature class B2 and more luminous ones down to temperature class B9. The original Case-Hamburg surveys (about 12,000 stars) also include some 2,000 evolved A-G stars, along with some white dwarfs, planetary nebulae, and Wolf-Rayet stars. It is worth noting that the definition of an OB star is not universal; for example, Vanbeveren et al. (1998, in "The Brightest Stars") define them as O-B2 V-IV, O-B3 III, O-B4 II, and all OBA Ib, Iab, Ia, and IaO stars. This table was created by the HEASARC in September 2017 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/V/125">CDS Catalog V/125</a> files obcat.dat, obmk.dat, obubvbet.dat and radvel.dat. This is a service provided by NASA HEASARC .