53 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Rochester | 1 | 124,136 | 121,391 | 0.41% | 2,198 | 56 | City |
| Rochester | 2 | 124,136 | 121,575 | 0.41% | 2,198 | 56 | City |
| Stewartville | 3 | 6,977 | 6,688 | 0.84% | 2,114 | 3 | City |
| Stewartville | 4 | 6,977 | 6,684 | 0.84% | 2,114 | 3 | City |
| Byron | 5 | 6,929 | 6,317 | 1.76% | 2,229 | 3 | City |
| Byron | 6 | 6,929 | 6,327 | 1.76% | 2,229 | 3 | City |
| Marion | 7 | 4,165 | 4,033 | -0.02% | 143 | 29 | Township |
| Marion | 8 | 4,165 | 4,031 | -0.02% | 143 | 29 | Township |
| Cascade | 9 | 2,848 | 2,839 | 0.46% | 247 | 12 | Township |
| Cascade | 10 | 2,848 | 2,837 | 0.46% | 247 | 12 | Township |
| Oronoco | 11 | 2,536 | 2,450 | -0.04% | 81 | 31 | Township |
| Oronoco | 12 | 2,536 | 2,448 | -0.04% | 81 | 31 | Township |
| Rochester | 13 | 2,283 | 2,077 | 2.19% | 127 | 18 | Township |
| Rochester | 14 | 2,283 | 2,079 | 2.19% | 127 | 18 | Township |
| Oronoco | 15 | 2,097 | 1,806 | 2.79% | 715 | 3 | City |
| Oronoco | 16 | 2,097 | 1,809 | 2.79% | 715 | 3 | City |
| Eyota | 17 | 2,031 | 2,002 | 0.3% | 1,203 | 2 | City |
| Eyota | 18 | 2,031 | 1,999 | 0.3% | 1,203 | 2 | City |
| Haverhill | 19 | 1,488 | 1,498 | 0.4% | 47 | 32 | Township |
| Haverhill | 20 | 1,488 | 1,498 | 0.4% | 47 | 32 | Township |
| New Haven | 21 | 1,296 | 1,257 | 0.78% | 38 | 34 | Township |
| New Haven | 22 | 1,296 | 1,260 | 0.78% | 38 | 34 | Township |
| Kalmar | 23 | 1,168 | 1,120 | 0.86% | 36 | 33 | Township |
| Kalmar | 24 | 1,168 | 1,123 | 0.86% | 36 | 33 | Township |
| Salem | 25 | 1,078 | 1,092 | 0.37% | 30 | 36 | Township |
| Salem | 26 | 1,078 | 1,090 | 0.37% | 30 | 36 | Township |
| High Forest | 27 | 945 | 970 | -0.42% | 24 | 40 | Township |
| High Forest | 28 | 945 | 968 | -0.42% | 24 | 40 | Township |
| Dover | 29 | 767 | 783 | -0.52% | 764 | 1 | City |
| Dover | 30 | 767 | 784 | -0.52% | 764 | 1 | City |
| Pleasant Grove | 31 | 735 | 752 | 0.27% | 21 | 36 | Township |
| Pleasant Grove | 32 | 735 | 751 | 0.27% | 21 | 36 | Township |
| Rock Dell | 33 | 686 | 682 | 0.15% | 19 | 36 | Township |
| Rock Dell | 34 | 686 | 684 | 0.15% | 19 | 36 | Township |
| Orion | 35 | 533 | 545 | -0.56% | 15 | 36 | Township |
| Orion | 36 | 533 | 546 | -0.56% | 15 | 36 | Township |
| Viola | 37 | 529 | 550 | -0.56% | 15 | 36 | Township |
| Viola | 38 | 529 | 549 | -0.56% | 15 | 36 | Township |
| Eyota | 39 | 503 | 488 | 0% | 15 | 34 | Township |
| Eyota | 40 | 503 | 487 | 0% | 15 | 34 | Township |
| Marion | 41 | 471 | 326 | 7.05% | 253 | 2 | CDP |
| Dover | 42 | 381 | 383 | -0.52% | 11 | 35 | Township |
| Dover | 43 | 381 | 385 | -0.52% | 11 | 35 | Township |
| Elmira | 44 | 366 | 349 | 1.67% | 10 | 35 | Township |
| Elmira | 45 | 366 | 349 | 1.67% | 10 | 35 | Township |
| Quincy | 46 | 339 | 328 | 0% | 9 | 36 | Township |
| Quincy | 47 | 339 | 328 | 0% | 9 | 36 | Township |
| Byron | 48 | 203 | 210 | -1.46% | 6 | 36 | Township |
| Byron | 49 | 203 | 210 | -1.46% | 6 | 36 | Township |
| Byron | 50 | 157 | 150 | 0.64% | 4 | 36 | Township |
| Byron | 51 | 157 | 150 | 0.64% | 4 | 36 | Township |
| Hammond | 52 | 128 | 131 | -0.78% | 800 | 0 | City |
| Hammond | 53 | 128 | 131 | -0.78% | 800 | 0 | City |
Rochester is the largest city in Olmsted County, with a population of 124,136.
Hammond is the smallest city in Olmsted County, with a population of 128.
There are 53 cities in Olmsted County, Minnesota.