Geomaterials—including soils, rocks, concrete, and snow—are porous, heterogeneous media that exhibit complex mechanical behavior and multiscale failure mechanisms under diverse multiphysics geological conditions. A deep and predictive understanding of deformation and failure processes in geomaterials is essential for addressing critical challenges in geophysics (e.g., fault slip, seismic rupture), geohazards (e.g., landslides, debris flows, and rock avalanches driven by climatic extremes), and geotechnical engineering (e.g., CO₂ storage, geothermal systems, and underground infrastructure). With the advancement of computational science, numerical modeling has become a cornerstone in modern geomechanics, providing vital links between experimental insights and field-scale applications. This minisymposium aims to bring together researchers and practitioners to present and discuss recent developments in computational methods for geomaterials and geohazard modeling. This minisymposium provides an open platform for interdisciplinary dialogue aimed at advancing computational tools and fundamental understanding in geomechanics, with the ultimate goal of supporting sustainable and resilient interactions with the Earth’s subsurface systems.