Fort McKinley is an unincorporated community and census designated place in Harrison Township in Montgomery County, Ohio, United States.

It was delineated as a census-designated place (CDP) at the 2000 census, when its population was 3,989.

Fort McKinley is part of the Dayton Metropolitan Statistical Area.

[4] According to the United States Census Bureau, the CDP had a total area of 1.3 square miles (3.4 km2), all land.

28.2% of all households were made up of individuals, and 9.8% had someone living alone who was 65 years of age or older.