Electrocatalysts for the oxygen reduction reaction (ORR) are essential in a variety of clean-energy devices, such as fuel cells and zinc–air batteries. Here we report poly(bis-2,6-diaminopyridinesulfoxide) as an active and stable ORR catalyst under alkaline conditions. It has no crossover effect of methanol, and CO toxicity is negligible, suggesting its potential as a cathode catalyst for alkaline fuel cells.