Identifiers: city · borough · CDP
| Rank | Community | Population |
|---|---|---|
| 1 | Johnstown (city), PA | 18,411 |
| 2 | Westmont (borough), PA | 4,982 |
| 3 | Windber (borough), PA | 3,941 |
| 4 | Ebensburg (borough), PA | 3,404 |
| 5 | Elim (CDP), PA | 3,364 |
| 6 | Belmont (CDP), PA | 2,771 |
| 7 | Nanty-Glo (borough), PA | 2,511 |
| 8 | Portage (borough), PA | 2,459 |
| 9 | Geistown (borough), PA | 2,363 |
| 10 | Southmont (borough), PA | 2,045 |
| 11 | Westwood (CDP), PA | 1,692 |
| 12 | Ferndale (borough), PA | 1,547 |
| 13 | Mundys Corner (CDP), PA | 1,532 |
| 14 | Ligonier (borough), PA | 1,513 |
| 15 | Vinco (CDP), PA | 1,487 |
| 16 | Oakland (CDP), PA | 1,481 |
| 17 | Boswell (borough), PA | 1,224 |
| 18 | University of Pittsburgh Johnstown (CDP), PA | 1,194 |
| 19 | Davidsville (CDP), PA | 1,145 |
| 20 | East Conemaugh (borough), PA | 1,082 |
Identifiers: city · borough · CDP
| Rank | Community | Population |
|---|---|---|
| 1 | Johnstown (city), PA | 18,411 |
| 2 | Westmont (borough), PA | 4,982 |
| 3 | Windber (borough), PA | 3,941 |
| 4 | Ebensburg (borough), PA | 3,404 |
| 5 | Elim (CDP), PA | 3,364 |
| 6 | Belmont (CDP), PA | 2,771 |
| 7 | Nanty-Glo (borough), PA | 2,511 |
| 8 | Portage (borough), PA | 2,459 |
| 9 | Geistown (borough), PA | 2,363 |
| 10 | Southmont (borough), PA | 2,045 |
| 11 | Westwood (CDP), PA | 1,692 |
| 12 | Ferndale (borough), PA | 1,547 |
| 13 | Mundys Corner (CDP), PA | 1,532 |
| 14 | Ligonier (borough), PA | 1,513 |
| 15 | Vinco (CDP), PA | 1,487 |
| 16 | Oakland (CDP), PA | 1,481 |
| 17 | Boswell (borough), PA | 1,224 |
| 18 | University of Pittsburgh Johnstown (CDP), PA | 1,194 |
| 19 | Davidsville (CDP), PA | 1,145 |
| 20 | East Conemaugh (borough), PA | 1,082 |