| 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 |
| Dauphin County | 251 798 | 237 813 | 13 985 | 5.9 |
| Berrysburg borough | 354 | 376 | - 22 | - 5.9 |
| Conewago township | 2 847 | 2 832 | 15 | 0.5 |
| Dauphin borough | 773 | 845 | - 72 | - 8.5 |
| Derry township | 21 273 | 18 408 | 2 865 | 15.6 |
| East Hanover township | 5 322 | 4 569 | 753 | 16.5 |
| Elizabethville borough | 1 344 | 1 467 | - 123 | - 8.4 |
| Gratz borough | 676 | 696 | - 20 | - 2.9 |
| Halifax borough | 875 | 911 | - 36 | - 4.0 |
| Halifax township | 3 329 | 3 449 | - 120 | - 3.5 |
| Harrisburg city | 48 950 | 52 376 | - 3 426 | - 6.5 |
| Highspire borough | 2 720 | 2 668 | 52 | 1.9 |
| Hummelstown borough | 4 360 | 3 981 | 379 | 9.5 |
| Jackson township | 1 728 | 1 797 | - 69 | - 3.8 |
| Jefferson township | 327 | 385 | - 58 | - 15.1 |
| Londonderry township | 5 224 | 4 926 | 298 | 6.0 |
| Lower Paxton township | 44 424 | 39 162 | 5 262 | 13.4 |
| Lower Swatara township | 8 149 | 7 072 | 1 077 | 15.2 |
| Lykens borough | 1 937 | 1 986 | - 49 | - 2.5 |
| Lykens township | 1 095 | 1 238 | - 143 | - 11.6 |
| Middle Paxton township | 4 823 | 5 129 | - 306 | - 6.0 |
| Middletown borough | 9 242 | 9 254 | - 12 | - 0.1 |
| Mifflin township | 662 | 676 | - 14 | - 2.1 |
| Millersburg borough | 2 562 | 2 729 | - 167 | - 6.1 |
| Paxtang borough | 1 570 | 1 599 | - 29 | - 1.8 |
| Penbrook borough | 3 044 | 2 791 | 253 | 9.1 |
| Pillow borough | 304 | 341 | - 37 | - 10.9 |
| Reed township | 182 | 259 | - 77 | - 29.7 |
| Royalton borough | 963 | 1 120 | - 157 | - 14.0 |
| Rush township | 180 | 201 | - 21 | - 10.4 |
| South Hanover township | 4 793 | 4 626 | 167 | 3.6 |
| Steelton borough | 5 858 | 5 152 | 706 | 13.7 |
| Susquehanna township | 21 895 | 18 636 | 3 259 | 17.5 |
| Swatara township | 22 611 | 19 661 | 2 950 | 15.0 |
| Upper Paxton township | 3 930 | 3 680 | 250 | 6.8 |
| Washington township | 2 047 | 1 816 | 231 | 12.7 |
| Wayne township | 1 184 | 847 | 337 | 39.8 |
| West Hanover township | 6 505 | 6 125 | 380 | 6.2 |
| Wiconisco township | 1 168 | 1 372 | - 204 | - 14.9 |
| Williams township | 1 135 | 1 146 | - 11 | - 1.0 |
| Williamstown borough | 1 433 | 1 509 | - 76 | - 5.0 |
| Source: U.S. Census Bureau | Prepared by: Pennsylvania State Data Center | |||