Manuel Komnenos Doukas (or Comnenus Ducas) (Greek: Μανουήλ Κομνηνός Δούκας, Manouēl Komnēnos Doukas) (c. 1187 – c. 1241), often inaccurately called Manuel Angelos (a name he never used), was ruler of Thessalonica from 1230 to 1237 and of Thessaly from 1239 until his death in c. 1241.
Manuel was a legitimate son of the sebastokratōr John Doukas. He was thus a first cousin of the emperors Isaac II Angelos and Alexios III Angelos, and a brother of Michael I Komnenos Doukas and Theodore Komnenos Doukas of Epirus. Probably after 1225 or 1227 he was given the court dignity of despotes by his brother, Theodore. At about the same time he married, perhaps as his second wife, Maria, the illegitimate daughter of Ivan Asen II of Bulgaria, helping to cement his brother's alliance with this country.
After his brother's defeat and capture by the Bulgarians at the Battle of Klokotnitsa in 1230, Manuel was allowed by Ivan Asen II to rule in Thessalonica and its environs with the title of despotes. At one point Manuel tried to establish contacts with the Papacy, but in 1232 the longstanding breach with the Eastern Patriarchate at Nicaea was finally healed.
Manuel ruled peacefully until 1237, when his widowed father-in-law Ivan Asen II married Irene, the daughter of the captive Theodore. At this point Theodore and his sons were released from captivity and resolved to recover the rule of Thessalonica. Manuel was unsuccessful in seeking the support of Prince Geoffrey II Villehardouin of Achaea, and was forced to flee to Asia Minor.
After a spell among the Seljuks of Rum and in Nicaea, Manuel returned to Greece with Nicaean support in 1239 and captured several fortresses including Larissa and Pharsalos from Theodore's son John Komnenos Doukas, establishing himself as ruler of Thessaly. Theodore and John had to agree to a division of the family lands. When Manuel died about 1241, the area passed into the hands of his other nephew, Michael II Komnenos Doukas of Epirus.
By his wife Maria of Bulgaria, Manuel may have had at least one daughter:
| Preceded by Theodore |
Ruler of Thessalonica 1230–1237 |
Succeeded by John |
| Preceded by John |
Ruler of Thessaly 1239–1241 |
Succeeded by Michael |