59 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Waukegan | 1 | 86,657 | 89,119 | -0.56% | 3,578 | 24.22 | City |
| Buffalo Grove | 2 | 42,080 | 43,085 | -0.47% | 4,402 | 9.56 | Village |
| Mundelein | 3 | 31,961 | 31,533 | 0.27% | 3,289 | 9.72 | Village |
| Highland Park | 4 | 30,350 | 30,155 | 0.13% | 2,481 | 12.23 | City |
| North Chicago | 5 | 30,218 | 30,712 | -0.33% | 3,780 | 8 | City |
| Gurnee | 6 | 29,885 | 30,654 | -0.51% | 2,211 | 13.51 | Village |
| McHenry | 7 | 28,858 | 27,340 | 1.06% | 1,946 | 14.83 | City |
| Lake Hills | 8 | 28,483 | 28,927 | -0.31% | 2,791 | 10.21 | Village |
| Vernon Hills | 9 | 26,579 | 26,823 | -0.18% | 3,435 | 7.74 | Village |
| Round Lake Beach | 10 | 26,502 | 27,204 | -0.53% | 5,254 | 5.04 | Village |
| Zion | 11 | 23,926 | 24,626 | -0.58% | 2,409 | 9.93 | City |
| Grayslake | 12 | 20,779 | 21,216 | -0.42% | 1,904 | 10.91 | Village |
| Libertyville | 13 | 20,181 | 20,558 | -0.37% | 2,291 | 8.81 | Village |
| Lake Zurich | 14 | 19,623 | 19,755 | -0.13% | 2,834 | 6.92 | Village |
| Lake Forest | 15 | 19,360 | 19,345 | 0.01% | 1,126 | 17.20 | City |
| Deerfield | 16 | 18,704 | 19,154 | -0.48% | 3,377 | 5.54 | Village |
| Round Lake | 17 | 18,255 | 18,692 | -0.47% | 3,283 | 5.56 | Village |
| Antioch | 18 | 14,979 | 14,613 | 0.49% | 1,817 | 8.24 | Village |
| Lindenhurst | 19 | 14,315 | 14,374 | -0.08% | 3,162 | 4.53 | Village |
| Beach Park | 20 | 13,938 | 14,235 | -0.42% | 1,970 | 7.08 | Village |
| Wauconda | 21 | 13,773 | 14,067 | -0.43% | 2,715 | 5.07 | Village |
| Gages Lake | 22 | 11,072 | 9,939 | 0.53% | 3,720 | 2.98 | CDP |
| Fox Lake | 23 | 10,692 | 10,974 | -0.52% | 1,365 | 7.83 | Village |
| Barrington | 24 | 10,326 | 10,700 | -0.72% | 2,237 | 4.62 | Village |
| Hawthorn Woods | 25 | 9,563 | 9,088 | 1% | 1,175 | 8.14 | Village |
| Lake Villa | 26 | 8,557 | 8,726 | -0.4% | 1,310 | 6.53 | Village |
| Long Grove | 27 | 8,203 | 8,352 | -0.36% | 662 | 12.39 | Village |
| Island Lake | 28 | 7,964 | 8,033 | -0.18% | 2,378 | 3.35 | Village |
| Lincolnshire | 29 | 7,890 | 7,945 | -0.14% | 1,730 | 4.56 | Village |
| Park City | 30 | 7,815 | 7,882 | -0.17% | 6,755 | 1.16 | City |
| Round Lake Park | 31 | 7,764 | 7,664 | 0.26% | 3,762 | 2.06 | Village |
| Volo | 32 | 7,554 | 6,209 | 3.69% | 1,832 | 4.12 | Village |
| Winthrop Harbor | 33 | 6,531 | 6,688 | -0.47% | 1,409 | 4.64 | Village |
| Lakemoor | 34 | 6,447 | 6,174 | 0.86% | 1,215 | 5.30 | Village |
| Johnsburg | 35 | 6,404 | 6,354 | 0.16% | 883 | 7.25 | Village |
| Lake Bluff | 36 | 5,483 | 5,610 | -0.45% | 1,345 | 4.08 | Village |
| Highwood | 37 | 5,450 | 5,084 | 1.36% | 7,569 | 0.72 | City |
| Grandwood Park | 38 | 5,438 | 5,114 | 0.29% | 3,763 | 1.45 | CDP |
| Kildeer | 39 | 4,575 | 4,079 | 2.21% | 1,061 | 4.31 | Village |
| Green Oaks | 40 | 4,027 | 4,109 | -0.4% | 1,009 | 3.99 | Village |
| Hainesville | 41 | 3,455 | 3,540 | -0.49% | 1,871 | 1.85 | Village |
| Wadsworth | 42 | 3,427 | 3,506 | -0.46% | 348 | 9.84 | Village |
| Pistakee Highlands | 43 | 3,252 | 3,302 | -0.4% | 2,533 | 1.28 | CDP |
| Long Lake | 44 | 2,795 | 3,065 | -1.69% | 2,369 | 1.18 | CDP |
| Venetian Village | 45 | 2,697 | 2,561 | -0.33% | 1,520 | 1.77 | CDP |
| Round Lake Heights | 46 | 2,547 | 2,616 | -0.55% | 4,430 | 0.57 | Village |
| Fox Lake Hills | 47 | 2,350 | 2,125 | -0.68% | 1,853 | 1.27 | CDP |
| Oakwood Hills | 48 | 2,043 | 2,068 | -0.24% | 1,878 | 1.09 | Village |
| Channel Lake | 49 | 1,814 | 1,784 | 0.55% | 1,006 | 1.80 | CDP |
| Knollwood | 50 | 1,767 | 1,684 | 0.06% | 2,921 | 0.60 | CDP |
| Lake Catherine | 51 | 1,294 | 1,289 | -0.46% | 1,424 | 0.91 | CDP |
| Forest Lake | 52 | 1,265 | 1,292 | -2.09% | 3,614 | 0.35 | CDP |
| Third Lake | 53 | 1,087 | 1,112 | -0.46% | 1,849 | 0.59 | Village |
| McCullom Lake | 54 | 958 | 982 | -0.52% | 2,761 | 0.35 | Village |
| Holiday Hills | 55 | 601 | 616 | -0.5% | 643 | 0.93 | Village |
| Mettawa | 56 | 552 | 531 | 0.73% | 101 | 5.45 | Village |
| Indian Creek | 57 | 523 | 530 | -0.19% | 1,959 | 0.27 | Village |
| Trout Valley | 58 | 505 | 514 | -0.39% | 1,180 | 0.43 | Village |
| Old Mill Creek | 59 | 160 | 164 | -0.62% | 15 | 10.66 | Village |
Waukegan is the largest city in Lake County, with a population of 86,657.
Old Mill Creek is the smallest city in Lake County.
There are 59 cities in Lake County, Illinois.