Gunnars þáttr Þiðrandabana (The Short Saga of Gunnar, Thidrandi's Killer) is a short saga (or þáttr) written in Old Norse in medieval Iceland. The events of the story take place in the Viking Age and concern Gunnar, a Norwegian merchant, who avenges his host's death in Iceland's Eastern Region, and must elude his enemies until he can safely escape the country.