Blackduck is a city in Beltrami County, Minnesota, United States.

The village of Blackduck was organized on October 19, 1900, and the city was incorporated on December 21, 1900.

There were 372 housing units at an average density of 222.8 per square mile (86.0/km2).

41.1% of all households were made up of individuals, and 22.1% had someone living alone who was 65 years of age or older.

There were 324 housing units at an average density of 216.8 per square mile (83.7/km2).

37.8% of all households were made up of individuals, and 19.7% had someone living alone who was 65 years of age or older.

The Blue Ox Trail goes through Blackduck for use by hikers and snowmobilers.

The old rail line includes the Minnesota and International Railway Bridge, which is on the National Register of Historic Places.