The strain rate sensitivity of a material arises from a thermally-activated contribution to the deformation processes, especially to dislocation slip. Nanocrystalline f.c.c. metals exhibit an increased strain rate sensitivity compared to coarse-grained equivalent due to the constraints on dislocation plasticity caused by the multitude of grain boundaries. In the following study, the extent to which hydrogen affects thermal-activated dislocation mobility and thus strain rate sensitivity was investigated. For this purpose, samples were charged in situ, both cathodically and by low-pressure hydrogen plasma, and subjected to nanoindentation, micropillar compression, and strain-rate jump macrotensile tests, and the results were contrasted. Hydrogen is shown to increase the strain rate sensitivity of f.c.c. metals.