The strain rate effect on the elastic modulus, indentation hardness, and micro creep of hardened cement paste was investigated via continuous stiffness measurement. The microstructure of the indentation zone was determined by scanning electron microscopy. The effect of microstructure on the mechanical and creep property was analyzed. The results show that the homogeneous mechanical properties of cement pastes can be measured via continuous stiffness measurement with a maximum depth of 30 μm. When the indentation depth (force) is greater than the critical minimum depth (force), the measured elastic modulus and indentation hardness will remain nearly a constant, reflecting the homogeneous mechanical properties of cement pastes. Within the strain rates ranging from 0.01 s–1 to 0.50 s–1, the strain rate has a negligible effect on the elastic modulus. However, the indentation hardness increases with increasing the strain rate, and their relationship can be well expressed by an empirical power law equation. Strain rate also affects the contact creep function during the holding stage. The greater the strain rate, the greater the contact creep function is, which is due to the fact that the creep will develop less during the loading stage at a greater strain rate. It is thus necessary to minimize the loading time to ensure correct measurement of the creep property. The findings can provide a reference to evaluate the strain rate effect on the mechanical and creep properties of cement pastes.