Phase-modulated voltammetry (PMV) permits direct electrochemical interrogation of excited-state oxidation and reduction potentials. The excited states examined include two organic triplet states (anthracene and triphenylene) and several inorganic metal-to-ligand charge-transfer states (RUL(3)(2+) where L = 2,2’-bipyridine (bpy), 4,4’-dimethyl-2,2’-bipyridine (dmb), phenanthroline (phen), or bipyrazine (bpz)). The redox potentials obtained in this analysis are roughly consistent with the excited-state potentials of these compounds calculated from the Rehm-Weller equation. PMV can also be used for the determination of excited-state energies for species that are spectroscopically inaccessible in room temperature solution.