On June 9-17, 2022 the Summer School “Mathematics of Complex Social Systems” took place at Zuse Institute Berlin. It was organized by Sarah Wolf (FU Berlin), Natasa Djurdjevac Conrad (ZIB), Stefanie Winkelmann (ZIB), Stefan Klus (U Surrey) and Luzie Helfmann (ZIB) as a part of the Thematic Einstein Semester. It brought together students from mathematics and related fields with a strong interest in societal phenomena and students from humanities or social sciences with a strong interest in quantitative research. Participants came from Germany, Austria, Great Britain, France, the Netherlands, Egypt and the USA. A program of lectures and hands-on sessions including network and agent-based models was completed by social events.