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Induced seismicity observed during Enhanced Geothermal Stimulation at Otaniemi, Finland is modeled using both statistical and physical approaches. The physical model produces simulations closest to the observations when assuming rate‐and‐state friction for shear failure with diffusivity matching the pressure build‐up at the well‐head at onset of injections. Rate‐and‐state friction implies a time‐dependent earthquake nucleation process which is found to be essential in reproducing the spatial pattern of seismicity. This implies that permeability inferred from the expansion of the seismicity triggering front (Shapiro et al., 1997, https://doi.org/10.1111/j.1365-246x.1997.tb01215.x) can be biased. We suggest a heuristic method to account for this bias that is independent of the earthquake magnitude detection threshold. Our modeling suggests that the Omori law decay during injection shut‐ins results mainly from stress relaxation by pore pressure diffusion. During successive stimulations, seismicity should only be induced where the previous maximum of Coulomb stress changes is exceeded. This effect, commonly referred to as the Kaiser effect, is not clearly visible in the data from Otaniemi. The different injection locations at the various stimulation stages may have resulted in sufficiently different effective stress distributions that the effect was muted. We describe a statistical model whereby seismicity rate is estimated from convolution of the injection history with a kernel which approximates earthquake triggering by fluid diffusion. The statistical method has superior computational efficiency to the physical model and fits the observations as well as the physical model. This approach is applicable provided the Kaiser effect is not strong, as was the case in Otaniemi. Plain Language Summary: Around 60,000 earthquakes are recorded during a span of 50 days where large volumes of water were injected underground for the stimulation of a geothermal well at Otaniemi, near Helsinki, Finland. We compare the observations with numerical simulations to analyze the physical processes that have driven these earthquakes. A model based on physics finds that it is important to use a friction law that includes friction's dependence on slip‐rate and state variables to match the observations. In particular, the model allows relating the spatio‐temporal evolution of seismicity with fluid pressure diffusion in the sub‐surface. An empirical statistical model is also developed using the recorded catalog. The statistical model is shown to perform well in the particular case of the Otaniemi stimulations. The models provide insight into the physical processes that govern induced seismicity. The models presented in this study could help safer operations or the design of mitigation and optimization strategies that may help improve the efficiency of geothermal energy extraction. Key Points: We model induced seismicity from a geothermal well stimulation operation near Helsinki, Finland, using physical and statistical approachesHydraulic diffusivity may be misestimated by the triggering front without accounting for nucleation effects from rate‐and‐state frictionNucleation effects are expected to be significant at short‐time scale injections commonly employed in geothermal well stimulation operations [ABSTRACT FROM AUTHOR]