Múlaþing
Municipality
Location of Múlaþing
Country	Iceland
Region	Eastern
Constituency	Northeast
Established	2020
Government
• Mayor	Björn Ingimarsson
Area
• Total	10,671 km2 (4,120 sq mi)
Population  (2020)[1]
• Total	5,000
• Density	0.47/km2 (1.2/sq mi)
Postal code(s)	700-710, 720, 765
Municipal number	7400
Website	mulathing.is

Múlaþing (Icelandic pronunciation: [ˈmuːlaˌθiŋk]) is a municipality in eastern Iceland which was formed in 2020 from the merger of Fljótsdalshérað, Seyðisfjörður, Borgarfjarðarhreppur and Djúpavogshreppur.

It is the second largest municipality in the country by area (the largest being Þingeyjarsveit). The biggest town in the municipality is Egilsstaðir, with a population of around 2,500. The second largest town of Seyðisfjörður is one of the oldest towns in Iceland.

The feral reindeer of Iceland are mostly situated in Fljótsdalshérað, where they number between 5,000 and 10,000. The largest forest in Iceland, Hallormsstaðaskógur is also located in Fljótsdalshérað.

The Kárahnjúkar Hydropower Plant is located in the municipality.