|Centuries:||2nd century – 3rd century – 4th century|
|Decades:||250s 260s 270s – 280s – 290s 300s 310s|
|Years:||284 285 286 – 287 – 288 289 290|
|287 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1040|
|Chinese calendar||丙午年 (Fire Horse)
2983 or 2923
— to —
丁未年 (Fire Goat)
2984 or 2924
|- Vikram Samvat||343–344|
|- Shaka Samvat||209–210|
|- Kali Yuga||3388–3389|
|Iranian calendar||335 BP – 334 BP|
|Islamic calendar||345 BH – 344 BH|
|Minguo calendar||1625 before ROC
|Seleucid era||598/599 AG|
|Thai solar calendar||829–830|
Year 287 (CCLXXXVII) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Valerius and Valerius (or, less frequently, year 1040 Ab urbe condita). The denomination 287 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 Diocletian and Maximian become Roman Consuls.
- Diocletian signs a peace treaty with Bahram II, king of Persia, and installs Tiridates III as king of Armenia.
- Diocletian re-organized the Mesopotamian frontier and fortifies the city of Circesium (modern Busayrah) on the Euphrates.
- September – The first Indiction begins.
- January 20 – Saint Sebastian, martyred
- Saint Maurice, Christian soldier (executed)
- Saints Victoricus, Fuscian, and Gentian, martyred