Constantinus Heraclius, known in English as Heraklonas, Heraclonas, or Heracleonas (626–641), is the son of Heraclius and his niece Martina, and is Byzantine Emperor briefly between February and September 641.

He was baptized and officially reigned as Constantinus Heraclius, but the diminutive nickname Heraklonas (Ἡρακλωνᾶς), little Heraclius, became established in Byzantine texts and has become standard in historiography.