Population by Municipality 2004
| Municipality | Population | Population Per Sq. Mile |
| Alburtis Borough | 2116 | 2784.210526 |
| Allentown City | 106476 | 5882.651934 |
| Bethlehem City* | 19282 | 3754.100052 |
| Catasauqua Borough | 6533 | 4912.030075 |
| Coopersburg Borough | 2562 | 2696.842105 |
| Coplay Borough | 3361 | 5334.920635 |
| Emmaus Borough | 11298 | 3978.169014 |
| Fountain Hill Borough | 4582 | 6028.947368 |
| Hanover Township | 1908 | 453.2066508 |
| Heidelberg Township | 3376 | 136.4591754 |
| Lower Macungie Township | 24398 | 1078.603006 |
| Lower Milford Township | 3796 | 192.494929 |
| Lowhill Township | 2067 | 146.0777385 |
| Lynn Township | 4174 | 100.0479386 |
| Macungie Borough | 3094 | 2891.588785 |
| North Whitehall Township | 15638 | 546.4011181 |
| Salisbury Township | 13699 | 1214.450355 |
| Slatington Borough | 4398 | 3075.524476 |
| South Whitehall Township | 18635 | 1083.430233 |
| Upper Macungie Township | 16195 | 618.8383645 |
| Upper Milford Township | 7252 | 408.3333333 |
| Upper Saucon Township | 13421 | 545.1259139 |
| Washington Township | 6809 | 289.4982993 |
| Weisenberg Township | 4584 | 170.917226 |
| Whitehall Township | 25590 | 1997.65808 |
| Allen Township | 3278 | 291.1190053 |
| Bangor Borough | 5291 | 3503.97351 |
| Bath Borough | 2766 | 3073.333333 |
| Bethlehem City* | 53510 | 3754.100052 |
| Bethlehem Township | 23176 | 1575.526852 |
| Bushkill Township | 7657 | 297.4747475 |
| Chapman Borough | 234 | 650 |
| East Allen Township | 4982 | 341.9354839 |
| East Bangor Borough | 989 | 1163.529412 |
| Easton City | 26298 | 6031.651376 |
| Forks Township | 12163 | 988.058489 |
| Freemansburg Borough | 1884 | 2478.947368 |
| Glendon Borough | 365 | 462.0253165 |
| Hanover Township | 9996 | 1500.900901 |
| Hellertown Borough | 5596 | 4207.518797 |
| Lehigh Township | 10399 | 349.19409 |
| Lower Mt Bethel Township | 3299 | 133.9967506 |
| Lower Nazareth Township | 5491 | 404.9410029 |
| Lower Saucon Township | 10864 | 443.9722109 |
| Moore Township | 9182 | 243.7483409 |
| Nazareth Borough | 6026 | 3565.680473 |
| North Catasauqua Borough | 2858 | 3862.162162 |
| Northampton Borough | 9662 | 3673.764259 |
| Palmer Township | 17987 | 1724.544583 |
| Pen Argyl Borough | 3641 | 2582.269504 |
| Plainfield Township | 5992 | 244.4716442 |
| Portland Borough | 574 | 989.6551724 |
| Roseto Borough | 1662 | 2596.875 |
| Stockertown Borough | 755 | 762.6262626 |
| Tatamy Borough | 1024 | 1796.491228 |
| Upper Mt Bethel Township | 6782 | 154.1013406 |
| Upper Nazareth Township | 5129 | 686.6131191 |
| Walnutport Borough | 2119 | 2682.278481 |
| Washington Township | 4585 | 255.147468 |
| West Easton Borough | 1169 | 3542.424242 |
| Williams Township | 5360 | 287.7079979 |
| Wilson Borough | 7746 | 6297.560976 |
| Wind Gap Borough | 2821 | 2059.124088 |
Source: U.S. Census and the Lehigh Valley Planning Commission Municipal Profiles