This proceedings volume brings together a broad and diverse collection of contributions that reflect the dynamism, strength, and growing interdisciplinarity of geochemistry in Mexico, as well as its international reach. The compiled works range from fundamental studies to cutting-edge applications in areas such as biogeochemistry, environmental and health geochemistry, hydrogeochemistry, geothermal studies, marine geochemistry, volcanology, geoarchaeology, petrology, isotopic geochemistry, and geochronology, in addition to the development and validation of advanced analytical methodologies. The contributions demonstrate the integration of innovative techniques, including mass spectrometry, isotopic analysis, advanced microscopy, metagenomics, remote sensing, and artificial intelligence, applied to the study of current issues of high scientific, environmental, and social relevance. These include contamination by potentially toxic elements, sustainable groundwater management, environmental and public health impacts, remediation of soils and water bodies, exploration of strategic and energy resources, as well as paleoenvironmental reconstruction and the regional geological evolution of Mexico. This volume highlights the geochemical community's commitment to sustainability, technological innovation, and human resource development, as evidenced by the numerous contributions from undergraduate and graduate students. The participation of these students, early-career researchers, and established research groups from diverse national and international institutions underscores the collaborative nature of the congress and its role as a platform for exchanging ideas, strengthening academic networks, and developing scientific solutions to complex challenges.