FM 2024 is the 26th international symposium on Formal Methods in a series organized by Formal Methods Europe (FME), an independent association whose aim is to stimulate the use of, and research on, formal methods for software development. The FM symposia have been successful in bringing together researchers and industrial users around a program of original papers on research and industrial experience, workshops, tutorials, reports on tools, projects, and ongoing doctoral research. FM 2024 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 experiences.