|Centuries:||4th century – 5th century – 6th century|
|Decades:||390s 400s 410s – 420s – 430s 440s 450s|
|Years:||423 424 425 – 426 – 427 428 429|
|426 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1179|
|Bahá'í calendar||−1418 – −1417|
|English Regnal year||N/A|
|Chinese calendar||乙丑年 (Wood Ox)
3122 or 3062
— to —
丙寅年 (Fire Tiger)
3123 or 3063
|- Vikram Samvat||482–483|
|- Shaka Samvat||348–349|
|- Kali Yuga||3527–3528|
|Igbo calendar||−574 – −573|
|Iranian calendar||196 BP – 195 BP|
|Islamic calendar||202 BH – 201 BH|
|Minguo calendar||1486 before ROC
|Thai solar calendar||969|
|Wikimedia Commons has media related to 426.|
Year 426 (CDXXVI) 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 Theodosius and Valentinianus (or, less frequently, year 1179 Ab urbe condita). The denomination 426 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 Theodosius II gives orders to destroy the buildings and pagan temples at Olympia (Greece). The statue of Zeus is brought to Constantinople.
- Flavius Aetius, Roman general (magister militum), starts a 10-year campaign against the Visigoths in southern Gaul.
- King Gunderic of the Vandals accepts the request of the Alans in Hispania to become their ruler (approximate date).
- K'inich Yax K'uk' Mo' becomes the founder of the pre-Columbian Maya civilization at Copán (modern Honduras).
- Augustine of Hippo publishes the De Civitate Dei, City of God.
- Sisinnius becomes Archbishop of Constantinople.
- Fu Liang, official of the Liu Song Dynasty (b. 374)
- Xie Hui, general of the Liu Song Dynasty (b. 390)
- Xu Xianzhi, official of the Liu Song Dynasty (b. 364)
- Zhang, empress dowager of the Liu Song Dynasty