The joint inversion of receiver function (RF) and surface‐wave dispersion data is popular because it reduces the nonuniqueness of the modeled subsurface‐seismic velocities. Whereas various inverse procedures have been used in joint subsurface imaging, the evaluation of uncertainties in the estimated parameter distribution is usually overlooked or considered qualitatively. We present a quantitative method for determination of uncertainty in velocity models estimated by the joint inversion of RF and surface‐wave data by using the prediction of each observation sample to map the objective‐function surface and create a statistical distribution of estimated model parameters. The proposed methodology is evaluated in a controlled test using synthetic data simulating a realistic shear‐wave velocity model. We then apply the method to field data recorded at the POPB seismic station in the Paraná Basin, southeast Brazil. The respective range of uncertainty for modeled S‐wave velocity distributions in the synthetic and field tests were 0.111–0.412 km/s (2.5%–9.2%), and 0.110–0.341 km/s (2.5%–7.9%).