We investigate the role of lanthanides and the surface area of perovskite oxides to determine the electrocatalytic properties in processes such as the oxygen reduction and evolution reactions. To evaluate the effects of A‐site lanthanide and the surface area, a series of lanthanide‐based perovskite nanoparticles (LnSCs) were successfully synthesized with simple co‐precipitation methods, and electrochemical tests were carried out with the LnSCs. According to the results, the catalytic activities are not affected by the A‐site lanthanides, but the surface area was found to be related to the current densities of the perovskite catalysts.