Muri District is a district in the Swiss Canton of Aargau with the administrative capital of Muri. It covers the central and southern part of Freiamt and has a population of 37,379 (as of 31 December 2020).

The Muri district has an area, as of 2009, of 138.96 square kilometers (53.65 sq mi). Of this area, 95.6 km2 (36.9 sq mi) or 68.8% is used for agricultural purposes, while 26.76 km2 (10.33 sq mi) or 19.3% is forested. Of the rest of the land, 13.62 km2 (5.26 sq mi) or 9.8% is settled (buildings or roads).

The blazon of the district coat of arms is Gules a Wall in fess embattled Argent masoned Sable..

The Muri district has a population (as of December 2020) of 37,379.