| Húnaþing vestra | |
| Settlement Type: | Municipality |
| Mapsize: | 250px |
| Pushpin Map: | Iceland |
| Coordinates: | 65.397°N -20.942°W |
| Subdivision Type: | Country |
| Subdivision Name: | Iceland |
| Subdivision Type1: | Region |
| Subdivision Name1: | Northwestern Region |
| Subdivision Type2: | Constituency |
| Subdivision Name2: | Northwest Constituency |
| Leader Title1: | Manager |
| Leader Name1: | Unnur Valborg Hilmarsdóttir |
| Unit Pref: | Metric |
| Area Total Km2: | 3,019 |
| Population Total: | 1,173 |
| Population Density Km2: | 0.39 |
| Postal Code Type: | Postal code(s) |
| Postal Code: | 500, 530, 531 |
| Code1 Name: | Municipal number |
| Code1 Info: | 5508 |
Húnaþing vestra (pronounced as /is/) is a municipality located in northern Iceland by Húnaflói gulf. It was founded on 7 June 1998 by the merging of all 7 of the old rural municipalities of Vestur-Húnavatnssýsla. They were: Staðarhreppur, Fremri-Torfustaðahreppur, Ytri-Torfustaðahreppur, Kirkjuhvammshreppur, Hvammstangahreppur, Þverárhreppur and Þorkelshólshreppur. On 1 January 2012, the municipality was merged with the county of Bæjarhreppur but kept the name Húnaþing vestra.
Húnaþing vestra consists of the three fjords Hrútafjörður og Miðfjörður, and Húnafjörður. Between are the peninsulas of Heggstaðanes and Vatnsnes. Its major settlement is Hvammstangi, but it also has the villages of Laugabakki, Reykir and Borðeyri.