Assuring Safe Autonomy contains papers presented at the 28th annual Safety-Critical Systems Symposium, held in York, UK, in February 2020. The Symposium is for engineers, managers and academics in the field of system safety, across all industry sectors, so the papers making up this volume offer wide coverage of current safety topics and a blend of academic research and industrial experience. They include both recent developments in the field and discussion of open issues and questions. The topics covered in this volume include: Assurance Cases, Autonomy, AI and Machine Learning, Data Safety, Human Factors, New Techniques and Security Informed Safety.