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.

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.