This book constitutes the refereed proceedings of the 20th International Conference on Economics of Grids, Clouds, Systems, and Services, GECON 2024, held in Rome, Italy, during September 26-27, 2024. The 12 full papers and 10 short papers presented in this book were carefully reviewed and selected from 37 submissions. They focus on topics such as: Function as a Service: Resource Management and QoS; Cloud Business Models, Pricing, Trading, Network Neutrality; Edge Computing and Energy Awareness; AI/Forecasting/Prediction Sales; and Resource Management in Cloud Applications: Simulation, Streaming Processing and Workflows.