324
| Years: 320 321 322 323 - 324 - 325 326 327 328 | |
| Decades: 290s 300s 310s - 320s - 330s 340s 350s | |
| Centuries: 3rd century - 4th century - 5th century | |
Events
- Constantine becomes the sole emperor of the Roman Empire. End of the Tetrarchy as the Roman mode of government.
- St Peter's Church, Rome, founded.
- Eustathius becomes bishop of Antioch
Deaths
- December 20 - Philogonus, Patriarch of Antioch
- Licinius, former Roman Emperor, executed for treason