Dumb Hundred is an unincorporated community and census-designated place (CDP) in Blair County, Pennsylvania, United States. It was first listed as a CDP prior to the 2020 census.
The CDP is in southern Blair County, in the southwestern part of Taylor Township. It sits along Pennsylvania Route 867, which leads north to Roaring Spring and south to Interstate 99 at St. Clairsville.
Dumb Hundred is in the western part of the Morrisons Cove valley, with Dunning Mountain rising to the west.
It is in the Spring Cove School District.