Zero electron kinetic energy spectroscopy has been used to study the XeCl- anion and the X1/2 electronic state of neutral XeCl. The spectrum is vibrationally resolved, yielding anion and neutral vibrational frequencies. With the aid of earlier scattering measurements for the neutral state we construct a Morse-Morse-switching-van der Waals model potential function for the anion from our spectroscopic data, for which R-m=3.57+/-0.03 Angstrom and epsilon=145.8+/-0.7 meV. This represents the first accurate experimental potential for the XeCl- anion.