64 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Rutland | 1 | 29,357 | 26,782 | 2.41% | 812 | 36 | Township |
| Ottawa | 2 | 18,763 | 18,821 | -0.06% | 1,260 | 15 | City |
| LaSalle | 3 | 13,164 | 13,401 | -0.2% | 781 | 17 | Township |
| Streator | 4 | 12,241 | 12,510 | -0.44% | 1,673 | 7 | City |
| Bruce | 5 | 11,705 | 11,919 | -0.15% | 689 | 17 | Township |
| Ottawa | 6 | 11,224 | 11,263 | 0.12% | 739 | 15 | Township |
| Peru | 7 | 10,041 | 10,143 | 0.15% | 575 | 17 | Township |
| Peru | 8 | 9,764 | 9,909 | -0.3% | 942 | 10 | City |
| LaSalle | 9 | 9,388 | 9,566 | -0.38% | 698 | 13 | City |
| South Ottawa | 10 | 8,346 | 8,346 | 0.19% | 424 | 20 | Township |
| Northville | 11 | 7,321 | 7,336 | 0.1% | 224 | 33 | Township |
| Mendota | 12 | 7,021 | 7,154 | -0.18% | 195 | 36 | Township |
| Mendota | 13 | 6,892 | 7,040 | -0.43% | 1,345 | 5 | City |
| Marseilles | 14 | 4,766 | 4,830 | -0.27% | 527 | 9 | City |
| Mission | 15 | 4,061 | 4,069 | 0.05% | 128 | 32 | Township |
| Oglesby | 16 | 3,609 | 3,692 | -0.47% | 723 | 5 | City |
| Rutland | 17 | 3,579 | 3,604 | 0.03% | 102 | 35 | Township |
| Seneca | 18 | 2,888 | 2,885 | 0.21% | 81 | 36 | Township |
| Otter Creek | 19 | 2,637 | 2,663 | -0.04% | 74 | 36 | Township |
| Earl | 20 | 2,431 | 2,453 | -0.08% | 65 | 37 | Township |
| Dayton | 21 | 2,413 | 2,406 | 0.21% | 114 | 21 | Township |
| Sheridan | 22 | 2,410 | 2,424 | -0.12% | 1,136 | 2 | Village |
| Seneca | 23 | 2,301 | 2,345 | -0.39% | 371 | 6 | Village |
| Utica | 24 | 1,947 | 1,933 | 0.1% | 108 | 18 | Township |
| Adams | 25 | 1,598 | 1,620 | 0% | 48 | 33 | Township |
| Earlville | 26 | 1,594 | 1,611 | -0.25% | 1,327 | 1 | City |
| Eagle | 27 | 1,444 | 1,465 | 0% | 46 | 31 | Township |
| Eden | 28 | 1,355 | 1,377 | -0.07% | 37 | 36 | Township |
| North Utica | 29 | 1,347 | 1,325 | 0.3% | 390 | 3 | Village |
| Troy Grove | 30 | 1,270 | 1,279 | 0% | 36 | 36 | Township |
| Serena | 31 | 1,121 | 1,121 | 0.18% | 30 | 37 | Township |
| Leland | 32 | 923 | 946 | -0.54% | 1,728 | 1 | Village |
| Farm Ridge | 33 | 825 | 838 | -0.24% | 24 | 35 | Township |
| Fall River | 34 | 785 | 789 | 0% | 39 | 20 | Township |
| Dimmick | 35 | 744 | 751 | -0.13% | 20 | 37 | Township |
| Tonica | 36 | 733 | 748 | -0.41% | 538 | 1 | Village |
| Freedom | 37 | 601 | 608 | 0% | 16 | 37 | Township |
| Miller | 38 | 583 | 587 | 0% | 17 | 35 | Township |
| Hope | 39 | 574 | 582 | -0.52% | 16 | 36 | Township |
| Wallace | 40 | 567 | 571 | 0% | 21 | 28 | Township |
| Grand Ridge | 41 | 506 | 516 | -0.39% | 1,095 | 0 | Village |
| Allen | 42 | 504 | 506 | 0.4% | 14 | 36 | Township |
| Dayton | 43 | 488 | 475 | -0.81% | 265 | 2 | CDP |
| Deer Park | 44 | 473 | 476 | 0% | 15 | 31 | Township |
| Sheridan | 45 | 455 | 461 | 0.22% | 13 | 36 | Township |
| Ophir | 46 | 438 | 441 | 0% | 13 | 35 | Township |
| Lostant | 47 | 429 | 433 | -0.23% | 380 | 1 | Village |
| Waltham | 48 | 416 | 420 | 0% | 12 | 36 | Township |
| Naplate | 49 | 412 | 419 | -0.48% | 2,528 | 0 | Village |
| Vermillion | 50 | 378 | 382 | 0% | 16 | 23 | Township |
| Richland | 51 | 342 | 346 | 0% | 14 | 24 | Township |
| Ransom | 52 | 308 | 310 | -0.32% | 308 | 1 | Village |
| Grand Rapids | 53 | 277 | 280 | 0% | 8 | 36 | Township |
| Meriden | 54 | 265 | 265 | 0% | 8 | 35 | Township |
| Cedar Point | 55 | 259 | 266 | -0.77% | 254 | 1 | Village |
| Serena | 56 | 258 | 137 | 7.5% | 1,049 | 0 | CDP |
| Rutland | 57 | 255 | 255 | 0% | 367 | 1 | Village |
| Osage | 58 | 241 | 243 | 0% | 6 | 38 | Township |
| Kangley | 59 | 228 | 233 | -0.44% | 874 | 0 | Village |
| Troy Grove | 60 | 221 | 224 | -0.45% | 322 | 1 | Village |
| Wedron | 61 | 181 | 170 | 7.1% | 349 | 1 | CDP |
| Dana | 62 | 156 | 159 | -0.64% | 709 | 0 | Village |
| Leonore | 63 | 120 | 123 | -0.83% | 1,348 | 0 | Village |
| Triumph | 64 | 106 | 82 | 7.07% | 711 | 0 | CDP |
Rutland is the largest city in LaSalle County, with a population of 29,357.
Triumph is the smallest city in LaSalle County, with a population of 106.
There are 64 cities in LaSalle County, Illinois.