Dagur Hjartarson (b. 1986) is an Icelandic novelist and poet. His debut novel, The Last Confession of Love (Síðasta ástarjátningin), was shortlisted for The European Union Prize for Literature in 2016. He has been awarded the Tomas Gudmundsson Poetry Prize and the Icelandic Literature Center's Newcomer's Grant as well as the Jon ur Vor Poetry Prize.

His most recent novel, Light Crawlers (Ljósagangur), was shortlisted for the Icelandic Literary Prize in 2022.

Dagur resides in Reykjavík and operates a small publishing house, Tunglið Forlag, alongside Ragnar Helgi Ólafsson. They maintain a unique publishing tradition, only releasing books during a full moon and printing a limited run of 69 copies. At the end of the night, any unsold copies are ceremonially burned.

Dagur is represented by Reykjavík Literary Agency.