Kish graphite, a waste (called dust) from a steelmaking process, can be simultaneously purified and functionalized by mechanochemical ball‐milling in the presence of iodine. The resultant iodinated Kish graphite (I‐Kish‐G) contains low content of impurities and high iodine content (1.83 at%, 16.17 wt%, energy dispersive X‐ray spectroscopy) with high crystallinity. It has high specific surface area (924.3 m2 g−1), indicating that I‐Kish‐G is significantly purified, functionalized, and exfoliated into a few graphitic layers. More importantly, I‐Kish‐G displays outstanding electrocatalytic activity for oxygen reduction reaction with long‐term durability and robustness against methanol crossover and CO poisoning effects in alkaline media. Using mechanochemical ball‐milling, waste Kish graphite (Kish‐G) is simply converted into high‐quality electrocatalyst for oxygen reduction reaction in alkaline media. Ball‐milling Kish‐G in the presence of iodine simultaneously purifies and functionalizes Kish‐G into iodinated Kish‐G (I‐Kish‐G) with low content of impurities, high iodine content, high degree of crystallinity, and high specific surface area.