In this paper, we study the spectrum of Hahn-Sturm-Liouville operators. In this context, it is shown that the regular symmetric Hahn-Sturm-Liouville operator is semi-bounded from below. Moreover, we give some conditions for the self-adjoint singular Hahn-Sturm-Liouville operator to have a discrete spectrum. The method of proof is based on the splittings technique. Finally, we investigate the continuous spectrum of this operator.