The latest knowledge of the surface geology of South Australia is displayed on the 2020 edition of the state geology map newly released by the Geological Survey of South Australia (GSSA). It is a product of the GSSA’s ongoing statewide geological mapping program to undertake detailed studies in strategically important regions of South Australia. This map provides a consistent baseline dataset for broad regional surface geology, presenting the entire state as a seamless geological coverage. The 1:2 million scale matches that of numerous other statewide mapping products delivered by the GSSA, including solid geology, regolith geology, special commodity and geophysical map releases. It delivers a broad-scale framework to assist with regional planning, geological interpretation and understanding the geological assets of South Australia. Considerable progress in the understanding of the state’s geology has been facilitated by numerous mapping, geochronological and geochemical studies as well as geophysical surveys undertaken by the GSSA. Areas in which the geology has been significantly updated since the last edition include the Gawler Ranges southern margin, the north-eastern part of Eyre Peninsula, the eastern Musgrave Province, the Mount Painter area, the Curnamona Province and parts of Yorke Peninsula. The 2020 map replaces the 2002 edition, and is the eighth version to be created since first release in 1899. This substantially improved edition has been compiled by Wayne Cowley, former Principal Geologist in the GSSA, who continuously revised and updated the 1:2 million surface geology dataset. It includes significant contributions from many GSSA geologists and data scientists. Jonathan Irvine (GSSA) and Lee Tily (Primary Industries and Regions South Australia) were responsible for the intricate cartography.