Based on topography and gravitational field data, model variations in the crust thickness of Mars and Venus were calculated using the Love numbers method. The method takes into account the adjustment of the planetary interior to loads on the surface and in the interior. Numerical modeling was carried out using the expansion in spherical harmonics of the topography and gravitational field data up to the 90th degree and order for Mars and up to the 70th degree and order for Venus. The topography of the crust–mantle boundary suggests partial Airy isostatic compensation. The model of the Martian crust is consistent with the interval of crustal thickness values under the site of the InSight station in the southwestern part of Elysium Planitia obtained from the results of a seismic experiment. The comparison with the available global models of the crust of Mars and Venus was carried out.