Lake Hart is an unincorporated town, formerly incorporated, in Monroe Township, Morgan County, in the U.S. state of Indiana.

On September 13, 1985, the former town was declared a legal Conservancy District per the Indiana Conservancy District Act in Morgan County Circuit Court under Cause # C84 C 443.

The purpose for the Hart Lake Conservancy District was amended in Morgan County Circuit Court on January 16, 1987, to include the legal purposes of procuring water and sewage service for the community.

While not an incorporated town, a Conservancy District is a legal governmental entity with a duly elected board of directors, has a tax base, is subject to the Indiana Governmental Agencies laws regarding budgeting, and is subject to audit by the State Board of Accounts.

Hart Lake is located southwest of Mooresville.