The Basel Quantum Metrology and Sensing Conference (BQMS 2020) will highlight the state of the art and most recent advances in quantum sensing and quantum metrology with atomic and solid-state spin systems. It will gather key global players in these fields and focus on both fundamental research and engineering relevant to these highly active fields of quantum technology development. The conference is hosted at the University of Basel, Switzerland, with its long tradition in quantum technologies and the nanosciences. BQMS-2020 will feature invited talks given by world-leading experts from Europe and overseas as well as contributed talks and posters selected from the submitted abstracts, all in a single, thematically focused session. The conference is open to all researchers in the field. It is organized in the framework of the ASTERIQS and MACQSIMAL projects of the EU Quantum Technologies Flagship with the goal to be a forum for the entire community.