Republic is an unincorporated community and census-designated place (CDP) in Fayette County, Pennsylvania, United States.

Pennsylvania Route 43, the Mon–Fayette Expressway, passes 3 miles (5 km) north of Republic, with access from Exit 22.

According to the United States Census Bureau, the CDP has a total area of 0.73 square miles (1.9 km2), all land.

There were 714 housing units at an average density of 965.3 per square mile (372.7/km2).

37.6% of all households were made up of individuals, and 22.6% had someone living alone who was 65 years of age or older.