Húnavatnshreppur (Icelandic pronunciation: [ˈhuːnaˌvasːˌr̥ɛhpʏr̥] ) is a former rural municipality located in northwestern Iceland.

The municipality was formed on 1 January 2006 by the union of the former municipalities of Sveinsstaðahreppur [ˈsveinsˌstaːðaˌr̥ehpʏr̥], Torfalækjarhreppur [ˈtʰɔrvaˌlaiːcar̥ˌr̥ɛhpʏr̥], Svínavatnshreppur [ˈsviːnaˌvasːˌr̥ɛhpʏr̥] and Bólstaðarhlíðarhreppur [ˈpoulˌstaːðarˌl̥iːðar̥ˌr̥ɛhpʏr̥]. In 2022, the municipality merged with Blönduós to form Húnabyggð.

Húnavatn is one of the largest Icelandic municipalities. Its southern borders touch the glaciers of Hofsjökull and Langjökull. In the south are situated also the hot springs in Hveravellir.

• Official website