Allison is an unincorporated community and census-designated place, which is located in Luzerne and Redstone townships in Fayette County, Pennsylvania, United States. It is situated 3 miles south of the borough of Brownsville. As of the 2010 census, the population was 625. The CDP includes the neighborhood of Allison Heights in Luzerne Township. Dunlap Creek flows through the center of the CDP, forming the border between Luzerne and Redstone townships.