An efficient and practical iodine‐promoted oxidative aromatization of pyrazolidin‐3‐ones and pyrazolines has been developed under metal‐free, additive‐free and external‐oxidant‐free conditions in good yields with a broad functional group tolerance. In this transformation, a series of functionalized arylpyrazole derivatives could be obtained successfully. More importantly, the current methodology can be utilized as a convenient handle to elaborate pharmaceutical candidates.