33 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Decatur | 1 | 67,165 | 70,927 | -1.11% | 1,545 | 43.48 | City |
| Decatur township | 2 | 45,241 | 47,520 | -0.8% | 1,557 | 29.07 | Township |
| Hickory Point township | 3 | 17,439 | 18,194 | -0.68% | 491 | 35.55 | Township |
| Long Creek township | 4 | 10,065 | 10,548 | -0.78% | 263 | 38.22 | Township |
| Mount Zion township | 5 | 6,948 | 7,197 | -0.56% | 104 | 66.58 | Township |
| Mount Zion | 6 | 5,787 | 6,014 | -0.77% | 1,356 | 4.27 | Village |
| Whitmore township | 7 | 4,123 | 4,306 | -0.72% | 115 | 35.87 | Township |
| South Wheatland township | 8 | 3,853 | 4,026 | -0.72% | 139 | 27.81 | Township |
| Forsyth | 9 | 3,579 | 3,728 | -0.83% | 1,156 | 3.10 | Village |
| Maroa township | 10 | 1,771 | 1,853 | -0.78% | 42 | 41.77 | Township |
| Harristown township | 11 | 1,673 | 1,756 | -0.83% | 60 | 28.09 | Township |
| Maroa | 12 | 1,499 | 1,576 | -0.99% | 850 | 1.76 | City |
| South Macon township | 13 | 1,389 | 1,460 | -0.79% | 41 | 33.77 | Township |
| Pleasant View township | 14 | 1,344 | 1,414 | -0.81% | 44 | 30.59 | Township |
| Friends Creek township | 15 | 1,309 | 1,371 | -0.68% | 27 | 49.28 | Township |
| Illini township | 16 | 1,292 | 1,334 | -0.31% | 35 | 36.67 | Township |
| Harristown | 17 | 1,237 | 1,309 | -1.12% | 688 | 1.80 | Village |
| Long Creek | 18 | 1,196 | 1,253 | -0.91% | 424 | 2.82 | Village |
| Macon | 19 | 1,102 | 1,171 | -1.25% | 870 | 1.27 | City |
| Warrensburg | 20 | 1,066 | 1,111 | -0.84% | 1,464 | 0.73 | Village |
| Blue Mound | 21 | 1,062 | 1,129 | -1.21% | 1,815 | 0.58 | Village |
| Oakley township | 22 | 938 | 979 | -0.64% | 33 | 28.73 | Township |
| Argenta | 23 | 858 | 910 | -1.15% | 1,314 | 0.65 | Village |
| Oreana | 24 | 837 | 887 | -1.18% | 1,788 | 0.47 | Village |
| Blue Mound township | 25 | 780 | 811 | -0.64% | 24 | 32.57 | Township |
| Niantic township | 26 | 720 | 752 | -0.55% | 25 | 29.11 | Township |
| Niantic | 27 | 575 | 609 | -1.2% | 553 | 1.04 | Village |
| Boody | 28 | 445 | 442 | 2.53% | 387 | 1.15 | CDP |
| Blue Mound township | 29 | 377 | 388 | -0.79% | 10 | 37.78 | Township |
| Austin township | 30 | 222 | 231 | -0.45% | 6 | 36.86 | Township |
| Macon township | 31 | 199 | 205 | -0.5% | 5 | 36.55 | Township |
| Elwin | 32 | 80 | 143 | 6.67% | 96 | 0.83 | CDP |
| Lake City | 33 | 49 | 107 | 6.52% | 127 | 0.39 | CDP |
Decatur is the largest city in Macon County, with a population of 67,165.
Lake City is the smallest city in Macon County.
There are 33 cities in Macon County, Illinois.