Year 319 (CCCXIX) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantinus and Licinius (or, less frequently, year 1072 Ab urbe condita). The denomination 319 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

• Emperor Constantine the Great prohibits the separation of the families of slaves, during a change in ownership.^{[citation needed]}

• King Chandragupta I succeeds his father Ghatotkacha, as ruler of the Gupta dynasty.

• Christianity is introduced in Colchis, present-day Georgia.

• Arius travels to Nicomedia at the invitation of Bishop Eusebius, after having been accused of heresy and condemned by Alexander, the Patriarch of Alexandria. This gives rise to the Arian Controversy.

• Murong Jun, Chinese emperor of the Former Yan (d. 360)

• Du Zeng, Chinese general and rebel leader
• Ghatotkacha, Indian ruler of the Gupta Empire
• Theodore Stratelates, Greek general and martyr (b. 281)