We analyze the interevent time distribution of hydraulic‐fracturing‐induced seismicity collected during 18 stages at four different regions. We identify a universal statistical process describing the distribution of hydraulic‐fracturing‐induced events in time. The distribution of waiting times between subsequently occurring events is given by the exponential probability density function of the homogeneous Poisson process. Our findings suggest that hydraulic‐fracturing‐induced seismicity is directly triggered by the relaxation of stress and pore pressure perturbation initially created by the injection. Therefore, compared to this relaxation, the stress transfer caused by the occurrence of preceding seismic events is mainly insignificant for the seismogenesis of subsequently occurring events. We develop a statistical model to compute the occurrence probability of hydraulic‐fracturing‐induced seismicity. This model can be used to assess the seismic hazard associated with hydraulic fracturing operations. No aftershock triggering has to be included in the statistical model. Key Points Statistical model to compute the occurrence probability of hydraulic‐fracturing‐induced seismicity Seismicity is triggered by relaxation of stress and pore pressure perturbation by injection No aftershocks have to be included in statistical models of hydro‐fracturing induced seismicity