The Hypatian Codex (also known as Hypatian Chronicle, Ipatiev Chronicle, Belarusian: Іпацьеўскі летапіс; Russian: Ипатьевская летопись; Ukrainian: Іпатіївський літопис, Іпатський літопис, Літопис руський за Іпатським списком) is a compendium of three chronicles: the Primary Chronicle, Kiev Chronicle, and Galician-Volhynian Chronicle. It is the most important source of historical data for southern Rus'. The codex was rediscovered in what is today Ukraine in 1617 and then copied by monks in Kyiv in 1621.
The codex is the second oldest surviving manuscript of the Primary Chronicle, after the Laurentian Codex. The Hypatian manuscript dates back to ca 1425, but it incorporates much precious information from the lost 12th-century Kievan and 13th-century Galician chronicles. The codex was possibly compiled at the end of the 13th century.
The Hypatian Codex was re-discovered again in the 18th century at the Hypatian Monastery of Kostroma by the Russian historian Nikolay Karamzin. Since 1810, the codex has been preserved in the Russian National Library, St Petersburg. The language of this work is Old Church Slavonic with many Slavisms.