65 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Waukegan | 1 | 89,900 | 90,186 | 0.29% | 4,253 | 21 | Township |
| Waukegan | 2 | 88,432 | 89,122 | -0.16% | 3,652 | 24 | City |
| Libertyville | 3 | 55,145 | 54,104 | 0.86% | 1,556 | 35 | Township |
| Ela | 4 | 46,797 | 45,333 | 0.9% | 1,361 | 34 | Township |
| Buffalo Grove | 5 | 43,066 | 43,094 | -0.01% | 4,505 | 10 | Village |
| Lake Villa | 6 | 40,155 | 39,773 | 0.55% | 1,764 | 23 | Township |
| Shields | 7 | 37,847 | 37,670 | 0.35% | 2,126 | 18 | Township |
| Moraine | 8 | 35,058 | 33,924 | 0.82% | 2,935 | 12 | Township |
| Fremont | 9 | 34,537 | 33,358 | 1.25% | 1,011 | 34 | Township |
| Mundelein | 10 | 32,916 | 31,539 | 0.84% | 3,009 | 11 | Village |
| West Deerfield | 11 | 32,014 | 31,560 | 0.72% | 1,799 | 18 | Township |
| Highland Park | 12 | 30,953 | 30,157 | 0.52% | 2,530 | 12 | City |
| North Chicago | 13 | 30,613 | 30,740 | -0.08% | 3,829 | 8 | City |
| Gurnee | 14 | 30,518 | 30,657 | -0.09% | 2,258 | 14 | Village |
| McHenry | 15 | 29,194 | 27,349 | 1.28% | 1,941 | 15 | City |
| Grant | 16 | 28,812 | 28,025 | 0.89% | 1,634 | 18 | Township |
| Lake in the Hills | 17 | 28,650 | 28,927 | -0.2% | 2,799 | 10 | Village |
| Antioch | 18 | 28,157 | 27,472 | 0.76% | 810 | 35 | Township |
| Round Lake Beach | 19 | 27,062 | 27,207 | -0.11% | 5,365 | 5 | Village |
| Vernon Hills | 20 | 27,046 | 26,825 | 0.16% | 3,496 | 8 | Village |
| Zion | 21 | 24,659 | 24,731 | 0.31% | 2,483 | 10 | Township |
| Wauconda | 22 | 24,649 | 23,637 | 1.13% | 1,082 | 23 | Township |
| Zion | 23 | 24,546 | 24,731 | -0.15% | 2,472 | 10 | City |
| Grayslake | 24 | 21,273 | 21,218 | 0.05% | 1,949 | 11 | Village |
| Libertyville | 25 | 20,663 | 20,563 | 0.1% | 2,346 | 9 | Village |
| Lake Zurich | 26 | 20,003 | 19,787 | 0.22% | 2,889 | 7 | Village |
| Lake Forest | 27 | 19,715 | 19,349 | 0.37% | 1,146 | 17 | City |
| Deerfield | 28 | 19,140 | 19,130 | 0.01% | 3,455 | 6 | Village |
| Round Lake | 29 | 18,644 | 18,691 | -0.05% | 3,353 | 6 | Village |
| Barrington | 30 | 16,372 | 16,477 | 0.81% | 470 | 35 | Township |
| Antioch | 31 | 15,230 | 14,617 | 0.81% | 1,848 | 8 | Village |
| Lindenhurst | 32 | 14,611 | 14,374 | 0.32% | 3,228 | 5 | Village |
| Beach Park | 33 | 14,206 | 14,235 | -0.04% | 2,008 | 7 | Village |
| Wauconda | 34 | 14,051 | 14,068 | -0.03% | 2,770 | 5 | Village |
| Fox Lake | 35 | 10,915 | 10,963 | -0.09% | 1,393 | 8 | Village |
| Barrington | 36 | 10,592 | 10,706 | -0.22% | 2,295 | 5 | Village |
| Hawthorn Woods | 37 | 9,707 | 9,091 | 1.28% | 1,193 | 8 | Village |
| Lake Villa | 38 | 8,739 | 8,726 | 0.02% | 1,338 | 7 | Village |
| Long Grove | 39 | 8,397 | 8,377 | 0.05% | 678 | 12 | Village |
| Island Lake | 40 | 8,073 | 8,036 | 0.09% | 2,411 | 3 | Village |
| Lincolnshire | 41 | 8,024 | 7,941 | 0.2% | 1,759 | 5 | Village |
| Park City | 42 | 7,954 | 7,881 | 0.18% | 6,875 | 1 | City |
| Round Lake Park | 43 | 7,879 | 7,664 | 0.55% | 3,817 | 2 | Village |
| Volo | 44 | 7,648 | 6,210 | 3.9% | 1,855 | 4 | Village |
| Newport | 45 | 6,835 | 6,816 | 0.43% | 215 | 32 | Township |
| Winthrop Harbor | 46 | 6,560 | 6,584 | -0.08% | 1,415 | 5 | Village |
| Lakemoor | 47 | 6,520 | 6,174 | 1.07% | 1,229 | 5 | Village |
| Johnsburg | 48 | 6,443 | 6,368 | 0.23% | 888 | 7 | Village |
| Lake Bluff | 49 | 5,597 | 5,609 | -0.05% | 1,373 | 4 | Village |
| Highwood | 50 | 5,425 | 5,087 | 1.25% | 7,535 | 1 | City |
| Kildeer | 51 | 4,672 | 4,080 | 2.59% | 1,083 | 4 | Village |
| Green Oaks | 52 | 4,106 | 4,110 | -0.02% | 1,029 | 4 | Village |
| Hainesville | 53 | 3,529 | 3,541 | -0.08% | 1,911 | 2 | Village |
| Wadsworth | 54 | 3,501 | 3,504 | -0.03% | 356 | 10 | Village |
| Round Lake Heights | 55 | 2,595 | 2,615 | -0.15% | 4,513 | 1 | Village |
| Oakwood Hills | 56 | 2,056 | 2,069 | -0.15% | 1,890 | 1 | Village |
| Third Lake | 57 | 1,113 | 1,116 | -0.09% | 1,893 | 1 | Village |
| McCullom Lake | 58 | 964 | 982 | -0.41% | 2,778 | 0 | Village |
| Holiday Hills | 59 | 603 | 616 | -0.5% | 646 | 1 | Village |
| Mettawa | 60 | 569 | 532 | 1.25% | 104 | 5 | Village |
| Indian Creek | 61 | 535 | 533 | 0% | 2,004 | 0 | Village |
| Trout Valley | 62 | 506 | 511 | -0.2% | 1,182 | 0 | Village |
| Russell | 63 | 355 | 389 | -1.39% | 10 | 36 | Township |
| Deerfield | 64 | 243 | 248 | 0% | 7 | 34 | Township |
| Old Mill Creek | 65 | 159 | 163 | -0.63% | 15 | 11 | Village |
Waukegan is the largest city in Lake County, with a population of 89,900.
Old Mill Creek is the smallest city in Lake County, with a population of 159.
There are 65 cities in Lake County, Illinois.