Alexios I Komnenos was a Byzantine emperor (1081–1118).

Alexios Komnenos (Ἀλέξιος Κομνηνός) or Alexius Comnenus may also refer to:

• Alexios Komnenos (governor of Dyrrhachium), nephew of Alexios I
• Alexios Komnenos (died 1136), son of Isaac Komnenos
• Alexios Komnenos (co-emperor), son of John II Komnenos
• Alexios Komnenos (son of Andronikos I), illegitimate son of Andronikos I Komnenos
• Alexios Komnenos (protosebastos), grandson of John II, lover of the Empress Maria Komnene and leader of her regency council
• Alexios II Komnenos, Byzantine emperor (1180–1183)
• Alexios Komnenos (died 1188), illegitimate son of Manuel I Komnenos
• Alexios I of Trebizond, Emperor of Trebizond (1204–1222)
• Alexios II of Trebizond, Emperor of Trebizond (1297–1330)
• Alexios III of Trebizond, Emperor of Trebizond (1349–1390)
• Alexios IV of Trebizond, Emperor of Trebizond (1417–1429)
• Alexios V of Trebizond, Emperor of Trebizond (1460)