We present accurate interaction potentials for uranium cations interacting with the rare gases (RG = He-Rn), using effective core potentials that include a description of the 5f electrons in the case of uranium, and justify this approximation in some detail. From these interaction potentials, spectroscopic parameters are derived for the U+-RG complexes. We also employ the potentials to calculate transport coefficients for U+ moving through a bath of each RG. In the case of U+ in He, we are able to compare with previous experimentally determined mobility values, and we make some minor corrections to the previously reported data; this revised data is presented.