Flat Iron is a small, unincorporated community in Highland Township, Vermillion County, in the U.S. state of Indiana.

A house and a pole barn occupy the site, along with a sign reading, "Flat Iron, population 1."

In the past the site had an additional residence and a general store, and a population of six.

Highland Airport, which closed in the late 1980s, was located just across the field to the north and east of Flat Iron.

The closest incorporated town is Perrysville, approximately three miles east.