Béla of Macsó (after 1243 – November 1272) was a member of the Rurik dynasty. He was Duke of Macsó (1262–1272) and of Bosnia (1266/1271-1272); and thus he governed the southern provinces of the Kingdom of Hungary.
Béla was the son of Duke Rostislav of Macsó and his wife, Anna, a daughter of King Béla IV of Hungary. When Duke Rostislav died in 1262, his lands were divided between his sons: Béla inherited the Banate of Macsó (including Belgrade and the Braničevo province), and his brother, Michael inherited their father’s part of Bosnia. King Béla IV, having made these assignments to his grandsons, decided also to make some further changes in his peripheral territories, and assigned Slavonia, Dalmatia, and Croatia, which until then had all been under his elder son and heir, Stephen V, to a younger son named Béla.
Stephen V was infuriated and immediately revolted against his father; during the ensuing war, Béla and his mother assisted Béla IV. His grandfather and uncle (Béla IV and Stephen V) concluded a peace on 5 December 1262, and according to the peace the kingdom was divided, the latter acquiring the territories east of the river Danube as “junior king”. After the peace, Stephen V occupied the possessions which Béla and his brother had inherited from their father in the eastern parts of the kingdom (the former royal possessions in Bereg County and the Castle of Füzér). Their mother submitted a formal complaint against her brother to Pope Urban IV, but the "junior king" did not hand back their possessions.