34 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Richland township | 1 | 15,231 | 15,092 | 0.26% | 430 | 35.43 | Township |
| Troy township | 2 | 11,985 | 11,944 | 0.14% | 278 | 43.04 | Township |
| Richland township | 3 | 5,180 | 5,041 | 0.64% | 187 | 27.75 | Township |
| Ohio township | 4 | 4,869 | 4,849 | 0.12% | 72 | 67.72 | Township |
| Richland township | 5 | 4,742 | 4,672 | 0.27% | 111 | 42.80 | Township |
| Troy township | 6 | 3,864 | 3,727 | 1.18% | 88 | 43.86 | Township |
| Richland township | 7 | 3,833 | 3,983 | -0.6% | 141 | 27.23 | Township |
| Carter township | 8 | 3,234 | 3,236 | 0.15% | 90 | 35.84 | Township |
| Clay township | 9 | 2,933 | 2,869 | 0.83% | 81 | 36.40 | Township |
| Santa Claus | 10 | 2,620 | 2,592 | 0.23% | 404 | 6.48 | Town |
| Luce township | 11 | 2,432 | 2,385 | 0.45% | 46 | 53.14 | Township |
| Rockport | 12 | 1,967 | 1,991 | -0.25% | 1,186 | 1.66 | City |
| Harrison township | 13 | 1,935 | 1,915 | 0.26% | 35 | 54.87 | Township |
| Richland township | 14 | 1,807 | 1,777 | 0.39% | 49 | 37.05 | Township |
| Dale | 15 | 1,508 | 1,542 | -0.46% | 624 | 2.42 | Town |
| Richland township | 16 | 1,300 | 1,249 | 0.93% | 55 | 23.50 | Township |
| Grass township | 17 | 1,122 | 1,117 | 0.09% | 25 | 45.36 | Township |
| Richland township | 18 | 1,089 | 1,095 | 0% | 29 | 37.48 | Township |
| Huff township | 19 | 1,062 | 1,048 | 0.28% | 25 | 42.36 | Township |
| Richland township | 20 | 1,031 | 1,091 | -1.62% | 26 | 39.65 | Township |
| Richland township | 21 | 892 | 898 | 0.11% | 38 | 23.75 | Township |
| Richland township | 22 | 831 | 829 | 0.36% | 16 | 51.94 | Township |
| Jackson township | 23 | 819 | 803 | 0.12% | 40 | 20.25 | Township |
| St. Meinrad | 24 | 806 | 707 | 0.88% | 479 | 1.68 | CDP |
| Grandview | 25 | 692 | 697 | -0.14% | 722 | 0.96 | Town |
| Hatfield | 26 | 568 | 772 | -2.74% | 485 | 1.17 | CDP |
| Richland township | 27 | 559 | 554 | 0.54% | 16 | 35.90 | Township |
| Chrisney | 28 | 470 | 465 | 0.21% | 666 | 0.71 | Town |
| Richland | 29 | 415 | 407 | 0.48% | 806 | 0.52 | Town |
| Richland township | 30 | 409 | 403 | 0.25% | 26 | 15.58 | Township |
| Troy | 31 | 370 | 347 | 1.37% | 327 | 1.13 | Town |
| Richland township | 32 | 339 | 324 | 1.5% | 12 | 28.52 | Township |
| Troy township | 33 | 325 | 312 | 0.93% | 22 | 14.90 | Township |
| Gentryville | 34 | 260 | 244 | 1.17% | 660 | 0.39 | Town |
Richland township is the largest city in Spencer County, with a population of 15,231.
Gentryville is the smallest city in Spencer County.
There are 34 cities in Spencer County, Indiana.