The Old Novgorod or Old Novgorodian dialect was the East Slavic variety used in the city of Veliky Novgorod and its surrounding area. It is mainly known from medieval birch bark writings dating to the 11th to 15th centuries. Andrey Zaliznyak distinguished it from "supra-dialectal Old Russian". Other manuscripts have also shown distinct north Russian dialect forms, in addition to the birch bark letters.
Old Novgorodian is of particular interest in that it has retained some archaic features which were lost in other Slavic dialects. For example, the birch bark letters from the Novgorod-Pskov area attest that the second palatalization failed to reach this area. Furthermore, the letters provide unique evidence of the Slavic vernacular, as opposed to the Church Slavonic which dominated the written literature of the period. Most of the letters feature informal writing such as personal correspondence, instructions, complaints, news, and reminders. Such widespread usage indicates a high level of literacy, even among women and children. The preserved notes display the original spelling of the time; unlike some texts, they were not copied, rewritten or edited by later scribes.
Today, the study of Novgorodian birch bark letters is an established scholarly field in Russian historical linguistics, with far-ranging historical and archaeological implications for the study of the Russian Middle Ages.