This book constitutes the proceedings of the 13th International Conference on Informatics in Schools: Situation, Evolution and Perspectives, ISSEP 2020, held in Tallinn, Estonia, in November 2020. Due to COVID-19 related travelling restrictions the conference had to be switched to online format. The 18 revised full papers presented were carefully reviewed and selected from 53 submissions. They are organized in topical sections named: Tasks for Informatics Competitions; Engagement and Gender Issues in School Informatics; Informatics Teacher Education; Curriculum and Pedagogical Issues.