Background: The treatment for internal carotid artery occlusion (ICAO) due to innominate artery stenosis is not well established. We herein describe a case of carotid–carotid crossover bypass and common carotid artery (CCA) ligation after mechanical thrombectomy for ICAO due to a plaque from the stenosed innominate artery. Case Description: A 70-year-old man was transferred to our hospital because of left-sided hemiparalysis. Head magnetic resonance imaging/angiography showed a cerebral infarction in the right middle cerebral artery area and the right ICAO due to a plaque from the stenosed innominate artery. Immediately, we performed mechanical thrombectomy and successfully attained partial revascularization (Thrombolysis in Cerebral Infarction Grade 2B). After a conference with cardiovascular group, we performed carotid–carotid crossover bypass and the right CCA ligation. The treatment was successful, and no complications occurred. Conclusion: Carotid–carotid crossover bypass and CCA ligation may be a better option for innominate artery stenosis in selected patients.