The Book of Armagh or Codex Ardmachanus (ar or 61), also known as the Canon of Patrick and the Liber Ar(d)machanus, is a 9th-century Irish illuminated manuscript written mainly in Latin. It is held by the Library of Trinity College, Dublin (MS 52). The document is valuable for containing early texts relating to St Patrick and some of the oldest surviving specimens of Old Irish, and for being one of the earliest manuscripts produced by an insular church to contain a near complete copy of the New Testament.