Efficiency of both water electrolyzers for low cost hydrogen generation as well as rechargeable metal-air batteries needs to be increased to further the pragmatic development of these key technologies. Given that the efficiencies of these technologies are limited primarily by the sluggish kinetics of the oxygen evolution reaction (OER), great efforts have been made to reduce the overpotentials for the OER in alkaline media with advanced catalysts. While precious metals such as Ir and Ru are standard OER catalysts in acidic electrolytes, alkaline electrolytes enable the use of earth-abundant, non-precious metals. Using selective substitution of A and B-sites within perovskite and perovskite derivatives to control the extent of hybridization between transition metal e_g and p(O) bands, we demonstrate exceptional OER activity. Furthermore, the enhanced covalency achieved through these substitutions leads to a new OER mechanism that utilizes lattice oxygen while the oxygen reduction activity is improved via increased contributions from the catalyst support.