This is The Southern Galaxy Catalogue, version 2.0, dated November 2019. It differs from previous versions in the following ways: 1) J2000.0 positions with precisions of 1 arcsecond are included rather than ESO-B positions with precisions of 0.1 arcminute. 2) Typical positional accuracy is on the order of 1-2 arcsec, though there are occasional "blunders" perhaps remaining. I will remove these as I (or others) stumble over them. 3) Diameters and axis ratios have been reduced to the B = 25.0 mag/sqarcsec systems of RC3 for compatibility with other lists. 4) The full types and luminosity classes are given rather than coded data as in the previous versions. 5) Position angles, usually from ESO-LV, are included. 6) V-band magnitudes and B-V colors from RC3; transformed from ESO-LV and/or 6dF B and R data; or, occasionally, from other sources are listed. 7) Redshifts given as V = cz, are usually taken from 6dF. Sources for the photometry and redshifts are also listed. The distribution includes five files: sgc20.txt -- the SGC, version 2.0; diameters and axis ratios given as logD (D in units of 0.1 arcminutes) and logR (R = D/d). sgc20am.txt -- the SGC, version 2.0; major and minor diameters given in arcminutes. sgc20.fmt -- a short example file for SGC. sgc20intro.txt -- This file. sgc20doc.txt -- documentation of this release. These files are 7-bit ASCII files. See the printed version (University of Texas Astronomy Department Monograph in Astronomy No. 4, 1985, by Harold G. Corwin, Jr., Antoinette de Vaucouleurs, and Gerard de Vaucouleurs) for more information and details.