Fuel cells are considered as the only viable solution for long-range electromobility, but very rare and expensive platinum is currently required for catalyzing the bottleneck reaction therein: oxygen reduction. Within the search for catalysts that are not based on precious metals, cobalt corroles were uncovered to fulfill the requirements of high selectivity and low overpotential. We now report on the electropolymerization of a specifically designed catalyst, a cobalt­(III) complex of tris­(4-aminophenyl)­corrole, upon which 3D polymeric structures were obtained. Much better catalytic activity was obtained by this approach in comparison to monomeric catalyst, manifested by significantly lower overpotentials, as well as higher selectivity to the desired 4e–/4H+ pathway. The performance in an alkaline environment makes it the most active molecular catalyst for the oxygen reduction reaction reported to date.