| Official Name: | Clappertown, Pennsylvania |
| Settlement Type: | Census-designated place |
| Pushpin Map: | Pennsylvania#USA |
| Pushpin Label: | Clappertown |
| Pushpin Label Position: | top |
| Coordinates: | 40.4028°N -78.2756°W |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Pennsylvania |
| Subdivision Type2: | County |
| Subdivision Name2: | Blair |
| Subdivision Type3: | Township |
| Subdivision Name3: | Huston |
| Area Footnotes: | [1] |
| Area Total Sq Mi: | 0.34 |
| Area Land Sq Mi: | 0.34 |
| Area Water Sq Mi: | 0.00 |
| Area Total Km2: | 0.89 |
| Area Land Km2: | 0.89 |
| Area Water Km2: | 0.00 |
| Population As Of: | 2020 |
| Population Density Km2: | 110.67 |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation Ft: | 1130 |
| Postal Code Type: | ZIP Code |
| Postal Code: | 16693 (Williamsburg) |
| Area Code: | 814/582 |
| Blank Name: | FIPS code |
| Blank Info: | 42-13728 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2805475 |
| Population Total: | 98 |
| Unit Pref: | Imperial |
| Population Density Sq Mi: | 286.55 |
Clappertown 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 eastern Blair County, in the northwestern part of Huston Township. It is in the Morrisons Cove region of the county, in the valley of Piney Creek, which flows north to the Frankstown Branch of the Juniata River at Ganister, part of the Susquehanna River watershed. Lock Mountain rises to an elevation of just west of Clappertown.
Pennsylvania Route 866 passes through the community, leading northeast 6miles to Wiliamsburg on the Frankstown Branch, and south-southeast 7miles to Martinsburg.