Hauksbók ('Book of Haukr'), Reykjavík, Stofnun Árna Magnússonar AM 371 4to, AM 544 4to and AM 675 4to, is an Icelandic manuscript, now in three parts but originally one, dating from the 14th century. It was created by the Icelander Haukr Erlendsson. It is now fragmentary, with significant portions being lost, but is the first surviving witness to many of the texts it contains (although in most cases Haukr is known to have been copying from earlier, lost manuscripts). Among these are the section on mathematics called Algorismus and the text of Hervarar saga ok Heiðreks.
Hauksbók is associated with an Icelandic lawspeaker named Haukr Erlendsson: although the work of several scribes, the vast majority is in Haukr's hand. Palaeographical evidence allowed Professor Stefán Karlsson, director of the Árni Magnússon Institute for Icelandic Studies, to date the manuscript to between 1302 and 1310. As long back as it is possible to trace the manuscript it has been called Hauksbók after him. Hauksbók is a compilation that includes Icelandic sagas and a redaction of the Landnámabók. The book contains versions, sometimes the only extant versions, of many Old Icelandic texts, such as the Fóstbrœðra saga, the Eiríks saga rauða, the Hervarar saga and the Völuspá. Haukr tended to rewrite the sagas that he copied, generally shortening them.
In addition, Haukr Erlendsson wrote "Hauk's Annals," which chronicled events of his lifetime and a handbook on Norse law.
The known contents of Hauksbók are: