Johnstown is a census-designated place (CDP) in Fremont County, Wyoming, United States.

As of the census[2] of 2000, there were 236 people, 83 households, and 60 families residing in the CDP.

The racial makeup of the CDP was 43.64% White, 53.39% Native American, and 2.97% from two or more races.

21.7% of all households were made up of individuals, and 4.8% had someone living alone who was 65 years of age or older.

About 11.3% of families and 17.8% of the population were below the poverty line, including 22.8% of those under the age of eighteen and 11.1% of those 65 or over.