After the success of the First Arab Winter School for astrophysics (FAWSA) in 2016 in Marrakech, the Second Arab Winter School for Astrophysics (AWSA-II) in 2017 in Ifrane (Morocco), and the Third ArAS School for Astrophysics in Beirut (Lebanon) in 2018, we are pleased to announce the Fourth ArAS School for Astrophysics (ArAS SfA-4) that will be held in the Kottamia Astronomical Observatory, Egypt October 19-26, 2019.