Many dams and geotechnical engineering structures are built for hydraulic engineering purposes. Therefore, the safety of dams and geotechnical engineering structures is particularly important when it comes to the normal engineering operation. This Special Issue focuses on the safety evaluation of dams and geotechnical engineering structures in the hydraulics and hydrodynamics field. The relevant topics include static and dynamic analysis; reliability analysis; risk analysis; seismic analysis; safety precautions; safety monitoring; safety operation; and safety evaluation methods.