The Book of Cuanu is a lost Irish Annal, which referred to events from the fifth to seventh centuries. It is referred to on over a dozen occasions in the Annals of Ulster, its entries having been terse accounts of battles or notable deaths.
In a short study concerning it, Eoghan O Mordha states that
<blockquote> "... by making use of the specific placename evidence in the entries attributed to the Book of Cuanu, it can be argued that, because the Cuanu entries display a bias towards recording events which took place for the most part in Lagin or the midlands, the entries can be regarded as being written somewhere in this general area." </blockquote>
The identity of Cuanu is uncertain.