Gnaeus Domitius Annius Ulpianus (c. 170 – 228), anglicized as Ulpian^{[pronunciation?]}, was a Roman jurist of Tyrian ancestry.

The exact time and place of his birth are unknown, but the period of his literary activity was between AD 211 and 222. He made his first appearance in public life as assessor in the auditorium of Papinian and member of the council of Septimius Severus; under Caracalla he was master of the requests (magister libellorum). Elagabalus (also known as Heliogabalus) banished him from Rome, but on the accession of Alexander (222) he was reinstated, and finally became the emperor's chief adviser and praefectus praetorio. His curtailment of the privileges granted to the Praetorian Guard by Elagabalus provoked their enmity, and he narrowly escaped their vengeance; ultimately he was murdered in the palace, in the course of a riot between the soldiers and the mob.

His works include: Ad Sabinum, a commentary on the jus civile, in over 50 books; Ad edictum, a commentary on the Edict, in 83 books; collections of opinions, responses and disputations; books of rules and institutions; treatises on the functions of the different magistrates — one of them, the De officio proconsulis libri x., being a comprehensive exposition of the criminal law; monographs on various statutes, on testamentary trusts, and a variety of other works. His writings altogether have supplied to Justinian's Digest about a third of its contents, and his commentary on the Edict alone about a fifth. As an author he is characterized by doctrinal exposition of a high order, judiciousness of criticism, and lucidity of arrangement, style and language. He is also credited with the first life table ever.