Maria Komnene (or Comnena) (Greek: Μαρία Κομνηνή, Maria Komnēnē; Constantinople, March 1152 – July 1182) was the eldest daughter of the Emperor Manuel I Komnenos by his first wife, Bertha of Sulzbach.
In 1163 she was engaged to the future King Béla III of Hungary; Manuel, no longer expecting to father a legitimate son, was at that time ready to designate Béla (whom he had given the new court dignity of despotes and had renamed "Alexios") as his eventual successor.
Finally, in 1179, Maria was married to Renier of Montferrat, who was renamed "John" and given the title of Caesar.
A riot broke out against the empress, encouraged by Maria and Renier, but their attempt to seize power failed.
Both died soon afterwards, apparently by poison, soon after the seizure of the regency by Andronikos Komnenos, a paternal first cousin of Manuel.