Flavius Ablabius or Ablavius (died in Constantinople, 338) was a high official of the Roman Empire.
Ablabius belonged to a poor, Pagan family, and originated from Crete. He converted to Christianity. He later become vicarius of Asia province. He was one of the most important officers of Emperor Constantine I, and held the Praetorian prefecture of the East from 329 to 337/338, and the consulship in 331.
Ablabius had some influence over Constantine. Once he succeeded to convince the Emperor that the lack of arrival of the grain supplies for Constantinople had been caused by the magical arts of Sopater of Apamea, a Pagan sage who had attacked both the Emperor and Ablabius for their dissolute behaviours. As suggested by Ablabius, Constantine put Sopater to death.
In 333 Constantine addressed to Ablabius a communication, still preserved today, in which the Emperor decreed that each party in a trial could appeal to a bishop's judgement.
In 337, Ablabius sided with Athanasius, the Nicene bishop of Alexandria, who had powerful enemies at the court of the Arian Emperor Constantius II, but he was deposed immediately after. In 338 he was condemned to death by Constantius (the accusation was false, as stated by Libanius) and executed in front of his house in Constantinople, which later belonged to Galla Placidia.
Ablabius had a daughter, Olympia, who was engaged to Emperor Constans (Constantius' brother and co-ruler). After 351 Constantius gave her as wife to King Arsaces II of Armenia, but soon she was poisoned by Arsaces's first wife.
| Preceded by Gallicanus, Aurelius Valerius Tullianus Symmachus |
Consul of the Roman Empire 331 Served alongside: Junius Annius Bassus |
Succeeded by Lucius Papius Pacatianus, Maecilius Hilarianus |
| Preceded by Constantius |
Praetorian prefect of the East 329-337/338 |
Succeeded by Septimius Acindynus |