Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Waukegan | 1 | 87,149 | 89,119 | -0.56% | 3,599 | 24.2 | City |
| Buffalo Grove | 2 | 42,281 | 43,085 | -0.47% | 4,423 | 9.6 | Village |
| Mundelein | 3 | 31,875 | 31,533 | 0.27% | 3,280 | 9.7 | Village |
| North Chicago | 4 | 30,317 | 30,712 | -0.33% | 3,792 | 8.0 | City |
| Highland Park | 5 | 30,311 | 30,155 | 0.13% | 2,478 | 12.2 | City |
| Gurnee | 6 | 30,039 | 30,654 | -0.51% | 2,223 | 13.5 | Village |
| Lake Hills | 7 | 28,572 | 28,927 | -0.31% | 2,800 | 10.2 | Village |
| McHenry | 8 | 28,554 | 27,340 | 1.07% | 1,926 | 14.8 | City |
| Round Lake Beach | 9 | 26,642 | 27,204 | -0.53% | 5,282 | 5.0 | Village |
| Vernon Hills | 10 | 26,628 | 26,823 | -0.18% | 3,442 | 7.7 | Village |
| Zion | 11 | 24,066 | 24,626 | -0.58% | 2,423 | 9.9 | City |
| Grayslake | 12 | 20,866 | 21,216 | -0.42% | 1,912 | 10.9 | Village |
| Libertyville | 13 | 20,256 | 20,558 | -0.37% | 2,300 | 8.8 | Village |
| Lake Zurich | 14 | 19,649 | 19,755 | -0.14% | 2,838 | 6.9 | Village |
| Lake Forest | 15 | 19,357 | 19,345 | 0.02% | 1,125 | 17.2 | City |
| Deerfield | 16 | 18,794 | 19,154 | -0.48% | 3,393 | 5.5 | Village |
| Round Lake | 17 | 18,342 | 18,692 | -0.48% | 3,299 | 5.6 | Village |
| Antioch | 18 | 14,906 | 14,613 | 0.49% | 1,809 | 8.2 | Village |
| Lindenhurst | 19 | 14,327 | 14,374 | -0.08% | 3,165 | 4.5 | Village |
| Beach Park | 20 | 13,997 | 14,235 | -0.43% | 1,978 | 7.1 | Village |
| Wauconda | 21 | 13,832 | 14,067 | -0.43% | 2,727 | 5.1 | Village |
| Gages Lake | 22 | 11,014 | 9,939 | 0.54% | 3,701 | 3.0 | CDP |
| Fox Lake | 23 | 10,748 | 10,974 | -0.53% | 1,372 | 7.8 | Village |
| Barrington | 24 | 10,401 | 10,700 | -0.72% | 2,253 | 4.6 | Village |
| Hawthorn Woods | 25 | 9,468 | 9,088 | 1.01% | 1,164 | 8.1 | Village |
| Lake Villa | 26 | 8,591 | 8,726 | -0.39% | 1,315 | 6.5 | Village |
| Long Grove | 27 | 8,233 | 8,352 | -0.36% | 665 | 12.4 | Village |
| Island Lake | 28 | 7,978 | 8,033 | -0.18% | 2,382 | 3.3 | Village |
| Lincolnshire | 29 | 7,901 | 7,945 | -0.14% | 1,732 | 4.6 | Village |
| Park City | 30 | 7,828 | 7,882 | -0.18% | 6,766 | 1.2 | City |
| Round Lake Park | 31 | 7,744 | 7,664 | 0.26% | 3,752 | 2.1 | Village |
| Volo | 32 | 7,285 | 6,209 | 3.83% | 1,767 | 4.1 | Village |
| Winthrop Harbor | 33 | 6,562 | 6,688 | -0.48% | 1,415 | 4.6 | Village |
| Johnsburg | 34 | 6,394 | 6,354 | 0.16% | 881 | 7.3 | Village |
| Lakemoor | 35 | 6,392 | 6,174 | 0.85% | 1,205 | 5.3 | Village |
| Lake Bluff | 36 | 5,508 | 5,610 | -0.47% | 1,351 | 4.1 | Village |
| Grandwood Park | 37 | 5,422 | 5,114 | 0.28% | 3,752 | 1.4 | CDP |
| Highwood | 38 | 5,377 | 5,084 | 1.38% | 7,468 | 0.7 | City |
| Kildeer | 39 | 4,476 | 4,079 | 2.26% | 1,038 | 4.3 | Village |
| Green Oaks | 40 | 4,043 | 4,109 | -0.42% | 1,013 | 4.0 | Village |
| Hainesville | 41 | 3,472 | 3,540 | -0.49% | 1,880 | 1.8 | Village |
| Wadsworth | 42 | 3,443 | 3,506 | -0.46% | 350 | 9.8 | Village |
| Pistakee Highlands | 43 | 3,265 | 3,302 | -0.4% | 2,543 | 1.3 | CDP |
| Long Lake | 44 | 2,843 | 3,065 | -1.66% | 2,409 | 1.2 | CDP |
| Venetian Village | 45 | 2,706 | 2,561 | -0.29% | 1,525 | 1.8 | CDP |
| Round Lake Heights | 46 | 2,561 | 2,616 | -0.54% | 4,454 | 0.6 | Village |
| Fox Lake Hills | 47 | 2,366 | 2,125 | -0.67% | 1,866 | 1.3 | CDP |
| Oakwood Hills | 48 | 2,048 | 2,068 | -0.24% | 1,882 | 1.1 | Village |
| Channel Lake | 49 | 1,804 | 1,784 | 0.56% | 1,000 | 1.8 | CDP |
| Knollwood | 50 | 1,766 | 1,684 | 0.11% | 2,919 | 0.6 | CDP |
| Lake Catherine | 51 | 1,300 | 1,289 | -0.38% | 1,430 | 0.9 | CDP |
| Forest Lake | 52 | 1,292 | 1,292 | -1.97% | 3,691 | 0.3 | CDP |
| Third Lake | 53 | 1,092 | 1,112 | -0.46% | 1,857 | 0.6 | Village |
| McCullom Lake | 54 | 963 | 982 | -0.52% | 2,775 | 0.3 | Village |
| Holiday Hills | 55 | 604 | 616 | -0.49% | 647 | 0.9 | Village |
| Mettawa | 56 | 548 | 531 | 0.73% | 101 | 5.5 | Village |
| Indian Creek | 57 | 524 | 530 | -0.38% | 1,963 | 0.3 | Village |
| Trout Valley | 58 | 507 | 514 | -0.39% | 1,185 | 0.4 | Village |
| Old Mill Creek | 59 | 161 | 164 | -0.62% | 15 | 10.7 | Village |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Waukegan is the largest city in Lake County.
Old Mill Creek is the smallest city in Lake County.
There are 59 cities in Lake County, Illinois.