| Borgarfjarðarhreppur | |
| Settlement Type: | Former municipality |
| Mapsize: | 250px |
| Pushpin Map: | Iceland |
| Coordinates: | 65.5261°N -13.8122°W |
| Subdivision Type: | Country |
| Subdivision Name: | Iceland |
| Subdivision Type1: | Region |
| Subdivision Name1: | Eastern Region |
| Subdivision Type2: | Constituency |
| Subdivision Name2: | Northeast Constituency |
| Subdivision Type3: | Municipality |
| Subdivision Name3: | Múlaþing |
| Leader Title1: | Manager |
| Leader Name1: | Jón Þórðarson |
| Unit Pref: | Metric |
| Area Total Km2: | 441 |
| Population Total: | 134 |
| Population Density Km2: | 0.30 |
| Postal Code Type: | Postal code(s) |
| Postal Code: | 720 |
Borgarfjarðarhreppur (pronounced as /is/) is a former municipality in Iceland.[1] In 2020 it merged with Djúpavogshreppur, Fljótsdalshérað, and Seyðisfjarðarkaupstaður to form the municipality of Múlaþing. Its main settlement is Bakkagerði. It is located in the Austurland region, in the eastern part of the country, 400 km east of Reykjavík, the country's capital.[2] The average temperature is -2 °C. The warmest month is July, at 9 °C, and the coldest month is February, at -8 °C.[3]