Húnavatnshreppur is a rural municipality located in north-western Iceland. The municipality was formed on January 1st 2006 by the union of the former municipalities of Sveinsstaðahreppur, Torfalækjarhreppur, Svínavatnshreppur and Bólstaðarhlíðarhreppur.
Húnavatn is one of the largest Icelandic municipalities. Its souther borders touch the glaciers of Hofsjökull and Langjökull. The hot springs in Hveravellir are situated in the southern part of the municipality .