| County | Rank | Change (2020) ↓ | 2025 Pop. | 2020 Pop. |
|---|---|---|---|---|
| Livingston Parish | 1 | 8.04% | 154,323 | 142,834 |
| St. Tammany Parish | 2 | 5.76% | 280,275 | 265,000 |
| Ascension Parish | 3 | 5.47% | 133,926 | 126,978 |
| West Baton Rouge Parish | 4 | 5.38% | 28,730 | 27,262 |
| Tangipahoa Parish | 5 | 5.19% | 140,594 | 133,654 |
| Lafayette Parish | 6 | 4.82% | 253,822 | 242,145 |
| De Soto Parish | 7 | 2.92% | 27,630 | 26,845 |
| Bossier Parish | 8 | 1.83% | 131,079 | 128,721 |
| Beauregard Parish | 9 | 1.72% | 37,233 | 36,605 |
| St. Bernard Parish | 10 | 1.58% | 44,551 | 43,856 |
| West Feliciana Parish | 11 | 0.41% | 15,321 | 15,259 |
| Vermilion Parish | 12 | 0.2% | 57,070 | 56,956 |
| LaSalle Parish | 13 | -0.44% | 14,758 | 14,823 |
| Lincoln Parish | 14 | -0.79% | 47,926 | 48,309 |
| East Feliciana Parish | 15 | -0.95% | 19,271 | 19,456 |
| St. Helena Parish | 16 | -1.41% | 10,744 | 10,898 |
| Iberville Parish | 17 | -1.46% | 29,625 | 30,064 |
| Sabine Parish | 18 | -1.49% | 21,770 | 22,099 |
| St. Landry Parish | 19 | -1.56% | 81,034 | 82,314 |
| Washington Parish | 20 | -1.64% | 44,613 | 45,357 |
| Ouachita Parish | 21 | -1.76% | 157,296 | 160,111 |
| St. Martin Parish | 22 | -1.86% | 50,673 | 51,634 |
| Grant Parish | 23 | -2.24% | 21,653 | 22,149 |
| Richland Parish | 24 | -2.29% | 19,568 | 20,026 |
| East Baton Rouge Parish | 25 | -2.34% | 445,219 | 455,899 |
| Acadia Parish | 26 | -2.54% | 56,017 | 57,478 |
| Jackson Parish | 27 | -2.61% | 14,606 | 14,998 |
| Union Parish | 28 | -2.84% | 20,492 | 21,092 |
| Franklin Parish | 29 | -2.91% | 19,139 | 19,713 |
| Evangeline Parish | 30 | -3.41% | 31,196 | 32,297 |
| Rapides Parish | 31 | -3.8% | 124,724 | 129,651 |
| Lafourche Parish | 32 | -3.89% | 93,666 | 97,454 |
| Allen Parish | 33 | -4.08% | 21,762 | 22,687 |
| Winn Parish | 34 | -4.18% | 13,146 | 13,720 |
| Jefferson Davis Parish | 35 | -4.37% | 30,801 | 32,210 |
| Caldwell Parish | 36 | -4.51% | 9,181 | 9,615 |
| Calcasieu Parish | 37 | -4.51% | 206,707 | 216,481 |
| Avoyelles Parish | 38 | -4.67% | 37,794 | 39,646 |
| Natchitoches Parish | 39 | -4.84% | 35,577 | 37,387 |
| St. Charles Parish | 40 | -5.27% | 49,744 | 52,513 |
| Pointe Coupee Parish | 41 | -5.31% | 19,576 | 20,673 |
| Iberia Parish | 42 | -5.31% | 66,337 | 70,055 |
| Claiborne Parish | 43 | -5.61% | 13,312 | 14,103 |
| Red River Parish | 44 | -5.86% | 7,138 | 7,582 |
| Jefferson Parish | 45 | -6.02% | 413,271 | 439,725 |
| Webster Parish | 46 | -6.03% | 34,660 | 36,883 |
| Plaquemines Parish | 47 | -6.56% | 21,922 | 23,460 |
| St. James Parish | 48 | -6.58% | 18,797 | 20,120 |
| Caddo Parish | 49 | -6.61% | 221,290 | 236,945 |
| Assumption Parish | 50 | -6.72% | 19,554 | 20,963 |
| West Carroll Parish | 51 | -7.11% | 9,007 | 9,696 |
| Terrebonne Parish | 52 | -7.15% | 101,584 | 109,405 |
| St. Mary Parish | 53 | -7.36% | 45,527 | 49,142 |
| Vernon Parish | 54 | -7.43% | 45,010 | 48,622 |
| Orleans Parish | 55 | -8% | 352,574 | 383,241 |
| Bienville Parish | 56 | -8.05% | 11,874 | 12,913 |
| St. John the Baptist Parish | 57 | -8.26% | 38,866 | 42,366 |
| Concordia Parish | 58 | -8.38% | 17,012 | 18,569 |
| Catahoula Parish | 59 | -9.16% | 8,034 | 8,844 |
| Morehouse Parish | 60 | -9.53% | 23,037 | 25,465 |
| East Carroll Parish | 61 | -10.65% | 6,609 | 7,397 |
| Tensas Parish | 62 | -10.79% | 3,664 | 4,107 |
| Madison Parish | 63 | -11.57% | 8,778 | 9,927 |
| Cameron Parish | 64 | -19.76% | 4,512 | 5,623 |
Louisiana's counties show varied growth patterns from 2020 to 2025. Livingston Parish leads with 8.04% annualized growth, followed by St. Tammany Parish (5.76%) and Ascension Parish (5.47%). The largest counties are East Baton Rouge Parish (445,219), Jefferson Parish (413,271), and Orleans Parish (352,574). Of the 64 counties in Louisiana, 12 are growing while 52 have experienced population decline. Overall, counties averaged -3.58% annualized growth, with total population growing by -2.3% annually.