Ectopic teeth are commonly found in the maxillary sinus and nasal cavity, while impacted third molars in the mandible are relatively rare. Cases of ectopic impaction of the third molar occurring in the condyle accompanied by dentigerous cysts are even rarer. This article reports a case of ectopic impacted third molar in the mandibular condyle with a dentigerous cyst, aiming to provide clinical doctors with diagnostic and treatment ideas for such conditions.