Hybrid Density Functional calculations have been performed on the electronic structure of anionic mono- (S, N, P, and C) and co-doped (N–N, N–P, N–S, P–P) SrTiO3 to improve their visible light photocatalytic activity. The electronic band position of doped system has been aligned with respect to the water oxidation/reduction potential. The electronic band position and optical absorption study shows that the mono- (S) and co-doped (N–N, N–P and P–P) SrTiO3 systems are promising materials for the visible-light photocatalysis. The calculated binding energies show that the co-doped systems are more stable than their respective mono-doped systems.