Harmon is a village in Lee County, Illinois, United States.

[2] According to the 2010 census, Harmon has a total area of 0.15 square miles (0.39 km2), all land.

There were 62 housing units at an average density of 436.8 per square mile (168.6/km2).

19.0% of all households were made up of individuals, and 8.6% had someone living alone who was 65 years of age or older.

There were 2.6% of families and 3.2% of the population living below the poverty line, including no under eighteens and 30.0% of those over 64.