ARGO-E GROUP was the publisher of the proceedings of the 9th International Congress on Environmental Geotechnics (9ICEG) that took place between June 25 and 28, 2023 in Chania, Crete, Greece. The International Congress on Environmental Geotechnics (ICEG) is the premier international event on environmental geotechnics and is organized by the Technical Committee 215 of the International Society of Soil Mechanics and Geotechnical Engineering (ISSMGE). The conference was held under the auspices of the Hellenic Society for Soil Mechanics and Geotechnical Engineering. Below you may find the individual paper files of the proceedings.