This book constitutes the refereed proceedings of the 18th Symposium and Summer School on Service-Oriented Computing, SummerSOC 2024, held in Crete, Greece, during June 24-29, 2024. The 8 revised full papers and 1 short paper presented in these proceedings were carefully reviewed and selected from 24 submissions. They cover the following topics: modeling the digital world; quantum computing; data platforms.