FM 2019 is the 23rd international symposium in a series organised by Formal Methods Europe (FME), an independent association whose aim is to stimulate the use of, and research on, formal methods for software development. Every 10 years the symposium is organised as a World Congress. Twenty years after FM’99 in Toulouse, and ten years after FM’09 in Eindhoven, FM’19 is the 3rd World Congress on Formal Methods. This is reflected in a Program Committee with members from over 40 countries. Thus, FM’19 will be both an occasion to celebrate and a platform for enthusiastic researchers and practitioners from a diversity of backgrounds to exchange their ideas and share their experience.