(Links below lead to Quick Facts for Connecticut Counties: People, Business & Geography at U.S. Census Bureau.)
| Area | 7/1/2008 | 7/1/2007 | 7/1/2006 | 7/1/2005 | 7/1/2004 | 7/1/2003 | 7/1/2002 | 7/1/2001 | 7/1/2000 | Census 2000 |
| Connecticut | 3,501,252 | 3,489,868 | 3,487,896 | 3,478,714 | 3,475,351 | 3,467,932 | 3,448,261 | 3,428,208 | 3,411,714 | 3,405,565 |
|---|---|---|---|---|---|---|---|---|---|---|
| Fairfield County | 895,030 | 890,595 | 890,512 | 891,838 | 892,946 | 892,776 | 890,913 | 888,226 | 884,481 | 882,567 |
| Hartford County | 877,312 | 875,075 | 872,945 | 870,496 | 868,418 | 868,490 | 864,543 | 861,209 | 858,439 | 857,183 |
| Litchfield County | 187,745 | 187,815 | 188,081 | 187,648 | 187,615 | 186,658 | 185,552 | 183,925 | 182,614 | 182,193 |
| Middlesex County | 164,794 | 163,827 | 163,128 | 161,930 | 161,299 | 160,707 | 159,141 | 157,020 | 155,615 | 155,071 |
| New Haven County | 846,101 | 844,358 | 841,881 | 840,117 | 838,814 | 837,452 | 832,371 | 828,441 | 824,985 | 824,008 |
| New London County | 264,519 | 263,770 | 267,877 | 265,204 | 266,672 | 265,149 | 262,945 | 260,901 | 259,536 | 259,088 |
| Tolland County | 148,406 | 147,583 | 147,212 | 146,384 | 145,714 | 144,374 | 141,900 | 138,700 | 136,852 | 136,364 |
| Windham County | 117,345 | 116,845 | 116,260 | 115,097 | 113,873 | 112,326 | 110,896 | 109,786 | 109,192 | 109,091 |
Source: Population Division, U.S. Census Bureau