Heraklonas or Heraclonas (Greek: Ηρακλωνάς, Hēraklōnas), (626– 641), Byzantine emperor (February–September 641), was the son of Herakleios and his niece Martina.

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

Heraklonas was probably born at Lazica while his father was on campaign against Khusrau II of the Sassanid Empire. He was probably the fourth son of Martina and Herakleios, but the first one born free of physical deformity and eligible for the throne.

Towards the end of Herakleios' reign he obtained through his mother’s influence the title of Augustus on July 4, 638, and after his father’s death was proclaimed joint emperor with his older half-brother Constantine III (Herakleios Constantine).

The premature death of Constantine III, in May 641, left Heraklonas sole ruler.