|Centuries:||2nd century – 3rd century – 4th century|
|Decades:||250s 260s 270s – 280s – 290s 300s 310s|
|Years:||283 284 285 – 286 – 287 288 289|
|286 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1039|
|Chinese calendar||乙巳年 (Wood Snake)
2982 or 2922
— to —
丙午年 (Fire Horse)
2983 or 2923
|- Vikram Samvat||342–343|
|- Shaka Samvat||208–209|
|- Kali Yuga||3387–3388|
|Iranian calendar||336 BP – 335 BP|
|Islamic calendar||346 BH – 345 BH|
|Minguo calendar||1626 before ROC
|Seleucid era||597/598 AG|
|Thai solar calendar||828–829|
Year 286 (CCLXXXVI) 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 Maximus and Aquilinus (or, less frequently, year 1039 Ab urbe condita). The denomination 286 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.
- April 1 – Emperor Diocletian elevates his friend Maximian to co-emperor, giving him the title Augustus. The Bagaudae are crushed, after their revolt in Gaul.
- Carausius, commander of the Classis Britannica, is accused of piracy and sentenced to death. He responds by declaring himself emperor of Britain and Northwestern Gaul. His forces consist of the newly built Roman fleet and three legions in Britain. The Carausian Revolt is supported by Gaulish merchant ships and barbarian mercenaries.
- Diocletian divides the empire in two, after economic and military problems. He gives Maximian control over the Western Roman Empire and appoints himself ruler of the Eastern Roman Empire (later known as the Byzantine Empire).
- Tuoba Xilu, chieftain of the Tuoba tribe and a member of the Xianbei people (present-day Mongolia)
- Crispin and Crispinian, patron saints of cobblers, martyred in Gallia Belgica (Southern Netherlands)