​This book constitutes the refereed proceedings of the 15th International Conference on Software Engineering and Formal Methods, SEFM 2017, held in Trento, Italy, in September 2017.The 17 full papers and 6 short papers presented were carefully reviewed and selected from 102 submissions. The papers deal with a large range of topics in the following research areas: new frontiers in software architecture; software verification and testing; software development methods; application and technology transfer; security and safety; and design principles.