Year 314 (CCCXIV) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Rufius and Annianus (or, less frequently, year 1067 Ab urbe condita). The denomination 314 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.
|Ab urbe condita||1067|
|Balinese saka calendar||235–236|
|Chinese calendar||癸酉年 (Water Rooster)|
3010 or 2950
— to —
甲戌年 (Wood Dog)
3011 or 2951
|- Vikram Samvat||370–371|
|- Shaka Samvat||235–236|
|- Kali Yuga||3414–3415|
|Iranian calendar||308 BP – 307 BP|
|Islamic calendar||318 BH – 316 BH|
|Minguo calendar||1598 before ROC|
|Seleucid era||625/626 AG|
|Thai solar calendar||856–857|
440 or 59 or −713
— to —
441 or 60 or −712
- October 8 – Battle of Cibalae: Constantine the Great defeats his rival Licinius near the town of Colonia Aurelia Cibalae (modern Vinkovci, Croatia). Licinius is forced to flee to Sirmium, and loses all of the Balkans except for Thrace. Peace negotiations are initiated between the two Augusti, but they are unsuccessful.
- A large Pictish raid southwards is attempted.
- January 11 – Pope Miltiades' reign ends.
- January 31 – Pope Sylvester I succeeds Pope Miltiades as the 33rd pope.
- August 30 – Council of Arles: Confirms the pronouncement of Donatism as a schism, and passes other canons.
- Synod of Ancyra: Consulting a magician is declared a sin earning five years of penance.
- Alexander becomes Bishop of Byzantium.