We investigate four metalloporphyrin (MP) catalysts containing manganese (MnP), iron (FeP), cobalt (CoP) and nickel (NiP). Manganese, iron, and cobalt porphyrins, including functionalized variants, have been explored extensively for the ORR. Nickel porphyrin has received only minimal attention as ORR catalysts due to its weak binding of O 2 , 7,21 yet its inclusion herein is useful as a way to cover the weak binding regime in the construction of LFESRs. Since MPs closely resemble pyrrolic MN 4 catalytic sites in M-N-C catalysts, we expect the conclusions drawn about the performance of different functionals to be relevant for this broader class of catalysts. Thus, the MPs considered herein comprise a valuable test set because they represent a class of notoriously complicated but widely studied 3d complexes spanning a range of ORR activities.