Understanding and estimating earthquake ground motions requires connecting observations of seismic shaking with models of wave propagation, local site conditions, and the uncertainties inherent in each. This session welcomes contributions on ground-motion characterization and estimation, site response, and the development and application of ground-motion models across a range of tectonic environments. Topics may include new and emerging GMMs; empirical approaches and physics-based ground-motion simulations; site amplification, resonance, and basin effects; site characterization using geophysical, geotechnical, or proxy datasets; microzonation; regional or earthquake-specific ground-motion studies. We also welcome contributions that explore how ground-motion characteristics and spatial variability influence secondary and earthquake-triggered hazards. We particularly encourage work exploring the incorporation of site-response information into PSHA (e.g. partially non-ergodic models), and the treatment of uncertainty in ground-motion modelling. Contributions examining consistency and regionalization of models across regions, as well as new datasets, machine-learning approaches, monitoring strategies, and comparisons between observations and simulations, are also welcome. The session aims to bring together researchers and practitioners working from fundamental observations and modelling through to applications in seismic-hazard assessment and engineering.