This book constitutes the proceedings of the 26th Italian Conference on Geomatics for Environmental Monitoring: From Data to Services, ASITA 2023, which was held as a virtual event during December 18-20, 2023. The 19 full papers included in this book were carefully reviewed and selected from 42 submissions. They were organized in topical sections as follows: Natural hazards monitoring and modelling; technological services for territory planning and Management; methodological advancements in data analysis and processing.