Emperor Alexius or Alexis may refer to:
Alexios I Komnenos (1048–1118), Byzantine emperor Alexios II Komnenos (1169–1183), Byzantine emperor Alexios III Angelos (1153–1211), Byzantine emperor Alexios IV Angelos (1182–1204), Byzantine emperor Alexios V (died 1205), Alexios Doukas Mourtzouphlos, Byzantine emperor Alexios I of Trebizond (1182–1222) Alexios II of Trebizond (1282–1330) Alexios III of Trebizond (1338–1390) Alexios IV of Trebizond (1382–1429) Alexis I of Russia (1629–1676), Alexei Mikhailovich Romanov