|Centuries:||4th century – 5th century – 6th century|
|Decades:||380s 390s 400s – 410s – 420s 430s 440s|
|Years:||415 416 417 – 418 – 419 420 421|
|418 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1171|
|Chinese calendar||丁巳年 (Fire Snake)
3114 or 3054
— to —
戊午年 (Earth Horse)
3115 or 3055
|- Vikram Samvat||474–475|
|- Shaka Samvat||340–341|
|- Kali Yuga||3519–3520|
|Iranian calendar||204 BP – 203 BP|
|Islamic calendar||210 BH – 209 BH|
|Minguo calendar||1494 before ROC
|Seleucid era||729/730 AG|
|Thai solar calendar||960–961|
Year 418 (CDXVIII) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Honorius and Theodosius (or, less frequently, year 1171 Ab urbe condita). The denomination 418 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 Honorius bribes Wallia, king of the Visigoths, into regaining Hispania for the Roman Empire. His victory over the Vandals in 416, forces him to retire to Andalusia. The Visigothic territory in Gaul now extends from the Garonne to the Loire, and becomes known as the Visigothic Kingdom.
- Theodoric I becomes king of the Visigoths. He complete the settlements in Gallia Aquitania and expands his military power to the south.
- In this year the Romans collected all the treasures which were in Britain, and hid some of them in the earth so that no one afterwards could find them, and some they took with them into Gaul.
- December 28 – Pope Boniface I succeeds Zosimus as the 42nd pope.
- Eulalius is elected antipope of Rome. He claims in a letter to Honorius his recognition as pope.