31 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Britton | 1 | 1,201 | 1,220 | -0.33% | 1,650 | 0.73 | City |
| Agency Village | 2 | 1,170 | 970 | 5.98% | 164 | 7.15 | CDP |
| Long Hollow | 3 | 407 | 395 | 3.56% | 28 | 14.43 | CDP |
| Veblen | 4 | 312 | 316 | -0.32% | 994 | 0.31 | City |
| Langford | 5 | 279 | 283 | -0.36% | 880 | 0.32 | Town |
| Lake township | 6 | 222 | 205 | 1.83% | 8 | 27.32 | Township |
| Red Iron Lake township | 7 | 222 | 204 | 1.83% | 7 | 31.13 | Township |
| Veblen township | 8 | 218 | 201 | 1.87% | 5 | 47.73 | Township |
| Weston township | 9 | 207 | 202 | 0.49% | 6 | 35.98 | Township |
| Stena township | 10 | 192 | 190 | 0% | 5 | 35.93 | Township |
| Pleasant Valley township | 11 | 188 | 175 | 1.62% | 5 | 35.81 | Township |
| Eden township | 12 | 175 | 177 | -1.13% | 5 | 34.85 | Township |
| Eden township | 13 | 121 | 107 | 3.42% | 4 | 31.37 | Township |
| Eden township | 14 | 100 | 99 | 0% | 3 | 33.38 | Township |
| Eden | 15 | 90 | 92 | 0% | 584 | 0.15 | Town |
| Waverly township | 16 | 77 | 69 | 2.67% | 2 | 35.96 | Township |
| La Belle township | 17 | 63 | 55 | 3.28% | 2 | 41.88 | Township |
| Newport township | 18 | 62 | 60 | 0% | 2 | 35 | Township |
| Eden township | 19 | 60 | 53 | 3.45% | 2 | 35.08 | Township |
| Dumarce township | 20 | 51 | 47 | 2% | 2 | 27.52 | Township |
| Lowell township | 21 | 51 | 52 | -1.92% | 1 | 36.14 | Township |
| Newark township | 22 | 50 | 48 | 0% | 1 | 35.74 | Township |
| Fort township | 23 | 44 | 42 | 0% | 2 | 29.13 | Township |
| Lake City | 24 | 43 | 43 | 0% | 196 | 0.22 | Town |
| Hickman township | 25 | 41 | 40 | 0% | 1 | 35.82 | Township |
| Victor township | 26 | 41 | 33 | 5.13% | 1 | 38.46 | Township |
| Wismer township | 27 | 38 | 32 | 5.56% | 2 | 17.04 | Township |
| Hamilton township | 28 | 36 | 35 | 0% | 1 | 31.18 | Township |
| Dayton township | 29 | 34 | 28 | 6.25% | 1 | 35.32 | Township |
| Nordland township | 30 | 34 | 28 | 6.25% | 1 | 23.39 | Township |
| McKinley township | 31 | 31 | 28 | 3.33% | 1 | 34.39 | Township |
Britton is the largest city in Marshall County, with a population of 1,201.
McKinley township is the smallest city in Marshall County.
There are 31 cities in Marshall County, South Dakota.