<p>Geological carbon dioxide storage in deep porous saline formations (deep saline aquifers) is generally considered a primary option for mitigating climate change, owing to the worldwide occurrence of these formations and the large CO₂ storage capacities attributed to them. In this study, a new assessment workflow is developed and applied to evaluate the offshore storage potential of three subsurface porous saline formations, e.g., Middle Jurassic, Middle Buntsandstein and Upper Rotliegend, within the German North Sea Sector. Using a three-dimensional structural geological model as well as depth-dependent petrophysical parameters, storage capacities and achievable injection rates are derived on a site-specific basis, yielding storage capacities of 0.15 ± 0.05 gigatonnes (Gt) for the Middle Jurassic, 12.2 ± 3.88 Gt for Middle Buntsandstein and 2.3 ± 0.8 Gt for the Upper Rotliegend storage formations. Achievable CO₂ injection rates per storage site using one injection borehole vary strongly with formation depth as well as the hydraulic regime and range from 0.2 to 20.9&#xa0;million tonnes per year (Mt/y). However, high injection rates are only found in the Middle Buntsandstein formation, marking it most suitable for Mt offshore storage applications. The average distance between the individual storage sites within each storage formation exceeds 100&#xa0;km, however for the sites with a storage capacity greater than 100 Mt the distance is approximately halved, indicating some spatial clustering of these sites. While the results presented here offer new insights into the offshore subsurface storage portfolio within the German North Sea sector, the approach is general and can be applied to all saline formations worldwide, serving as a tool for improved storage site assessment, prioritisation and utilisation.</p>