[1]​ Según el censo de 2000[2]​, el condado cuenta con 369.993 habitantes, 149.813 hogares y 104.569 familias residentes.

Hay 161.058 unidades habitacionales con una densidad promedio de 61 u.a./km² (157 u.a./mi²).

De los 149.813 hogares, en el 28,40% de ellos viven menores de edad, 57,00% están formados por parejas casadas que viven juntas, 9,60% son llevados por una mujer sin esposo presente y 30,20% no son familias.

Arnold | Greensburg | Jeannette | Latrobe | Lower Burrell | Monessen | New Kensington Adamsburg | Arona | Avonmore | Bolivar | Delmont | Derry | Donegal | East Vandergrift | Export | Hunker | Hyde Park | Irwin | Laurel Mountain | Ligonier | Madison | Manor | Mount Pleasant | Murrysville | New Alexandria | New Florence | New Stanton | North Belle Vernon | North Irwin | Oklahoma | Penn | Scottdale | Seward | Smithton | South Greensburg | Southwest Greensburg | Sutersville | Trafford‡ | Vandergrift | West Leechburg | West Newton | Youngstown | Youngwood Allegheny | Bell | Cook | Derry | Donegal | East Huntingdon | Fairfield | Hempfield | Ligonier | Loyalhanna | Mount Pleasant | North Huntingdon | Penn | Rostraver | St.

Clair | Salem | Sewickley | South Huntingdon | Unity | Upper Burrell | Washington Calumet-Norvelt | Crabtree | Collinsburg | Fellsburg | Grapeville | Harrison City | Herminie | Hostetter | Lawson Heights | Level Green | Loyalhanna | Lynnwood-Pricedale‡ | McChesneytown-Loyalhanna | Mammoth | Millwood | Norvelt | Slickville | Webster | Yukon Acme | Boquet | Calumet | Hannastown | Hopewell | Hutchinson | Kecksburg | Lloydsville | Luxor | Moween | Norvelt | Ruffs Dale | Southwest | Stahlstown | Standard Shaft | Salina | Turkeytown | United