Year 302 (CCCII) was a common year starting on Thursday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and Valerius or, less frequently, year 1055 Ab urbe condita. The denomination 302 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||1055|
|Balinese saka calendar||223–224|
|Chinese calendar||辛酉年 (Metal Rooster)|
2998 or 2938
— to —
壬戌年 (Water Dog)
2999 or 2939
|- Vikram Samvat||358–359|
|- Shaka Samvat||223–224|
|- Kali Yuga||3402–3403|
|Iranian calendar||320 BP – 319 BP|
|Islamic calendar||330 BH – 329 BH|
|Minguo calendar||1610 before ROC|
|Seleucid era||613/614 AG|
|Thai solar calendar||844–845|
428 or 47 or −725
— to —
429 or 48 or −724
- Emperor Diocletian persecutes the Manichaeans, accusing them of being a Persian fifth column.
- Caesar Galerius wins his second victory over the Carpi.
- An invasion of Gaul by the Alemannic Lingones almost traps Caesar Constantius I between the enemy and the walls of a town. Constantius himself is carried onto the wall via a crane. However, within the same day, Constantius sallies forth from the walls and defeats the enemy in a major battle.
- Narseh, ruler (Shahanshah) of the Sassanid Empire, dies after a 9-year reign. He is succeeded by his son Hormizd II.