| Population Change 1990-2000 | ||||
| County or Municipality | 2000 Population | 1990 Population | Population Change | Percent Change |
| Pennsylvania | 12 281 054 | 11 881 643 | 399 411 | 3.4 |
| Columbia County | 64 151 | 63 202 | 949 | 1.5 |
| Ashland borough | 0 | 3 | - 3 | - 100.0 |
| Beaver township | 885 | 928 | - 43 | - 4.6 |
| Benton borough | 955 | 958 | - 3 | - 0.3 |
| Benton township | 1 216 | 1 094 | 122 | 11.2 |
| Berwick borough | 10 774 | 10 976 | - 202 | - 1.8 |
| Bloomsburg town | 12 375 | 12 439 | - 64 | - 0.5 |
| Briar Creek borough | 651 | 616 | 35 | 5.7 |
| Briar Creek township | 3 061 | 3 010 | 51 | 1.7 |
| Catawissa borough | 1 589 | 1 683 | - 94 | - 5.6 |
| Catawissa township | 944 | 1 037 | - 93 | - 9.0 |
| Centralia borough | 21 | 63 | - 42 | - 66.7 |
| Cleveland township | 1 004 | 997 | 7 | 0.7 |
| Conyngham township | 792 | 1 038 | - 246 | - 23.7 |
| Fishing Creek township | 1 393 | 1 378 | 15 | 1.1 |
| Franklin township | 597 | 624 | - 27 | - 4.3 |
| Greenwood township | 1 932 | 1 972 | - 40 | - 2.0 |
| Hemlock township | 1 874 | 1 546 | 328 | 21.2 |
| Jackson township | 598 | 508 | 90 | 17.7 |
| Locust township | 1 410 | 1 308 | 102 | 7.8 |
| Madison township | 1 590 | 1 565 | 25 | 1.6 |
| Main township | 1 289 | 1 241 | 48 | 3.9 |
| Mifflin township | 2 251 | 2 305 | - 54 | - 2.3 |
| Millville borough | 991 | 969 | 22 | 2.3 |
| Montour township | 1 437 | 1 419 | 18 | 1.3 |
| Mount Pleasant township | 1 459 | 1 383 | 76 | 5.5 |
| North Centre township | 2 009 | 1 860 | 149 | 8.0 |
| Orange township | 1 148 | 1 043 | 105 | 10.1 |
| Orangeville borough | 500 | 504 | - 4 | - 0.8 |
| Pine township | 1 092 | 990 | 102 | 10.3 |
| Roaring Creek township | 495 | 478 | 17 | 3.6 |
| Scott township | 4 768 | 4 423 | 345 | 7.8 |
| South Centre township | 1 972 | 1 891 | 81 | 4.3 |
| Stillwater borough | 194 | 223 | - 29 | - 13.0 |
| Sugarloaf township | 885 | 730 | 155 | 21.2 |
| Source: U.S. Census Bureau | Prepared by: Pennsylvania State Data Center | |||