Lucas County Courthouse Square Historic District is a nationally recognized historic district located in Chariton, Iowa, United States.

The buildings were either built or remodeled between 1867 and 1963, and range from one to three stories in height.

Of the older buildings, the commercial Italianate style is dominant.

While the vast majority of the buildings are commercial buildings, there are five public buildings in the district: the Lucas County Courthouse (1893), Chariton Free Public Library (1904), the former Lucas County Sheriffs Residence and Jail (1916), the U.S. Post Office (1918), and Chariton City Hall and Fire Station (1931).

This article about a property in Lucas County, Iowa on the National Register of Historic Places is a stub.