We present the first data release of the SkyMapper Southern Survey, a hemispheric survey carried out with the SkyMapper Telescope at Siding Spring Observatory in Australia. Here, we present the survey strategy, data processing, catalogue construction, and database schema. The first data release dataset includes over 66000 images from the Shallow Survey component, covering an area of 17200 deg^2^ in all six SkyMapper passbands uvgriz, while the full area covered by any passband exceeds 20000 deg^2^. The catalogues contain over 285 million unique astrophysical objects, complete to roughly 18mag in all bands. We compare our griz point-source photometry with Pan-STARRS1 first data release and note an RMS scatter of 2%. The internal reproducibility of SkyMapper photometry is on the order of 1%. Astrometric precision is better than 0.2arcsec based on comparison with Gaia first data release. We describe the end-user database, through which data are presented to the world community, and provide some illustrative science queries.