16 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Pittsfield | 1 | 3,985 | 4,173 | -0.77% | 833 | 5 | City |
| Barry | 2 | 1,232 | 1,294 | -0.81% | 860 | 1 | City |
| Griggsville | 3 | 1,031 | 1,091 | -0.96% | 932 | 1 | City |
| Pleasant Hill | 4 | 895 | 924 | -0.56% | 1,170 | 1 | Village |
| Hull | 5 | 366 | 387 | -0.81% | 201 | 2 | Village |
| New Canton | 6 | 320 | 331 | -0.62% | 363 | 1 | Town |
| Perry | 7 | 301 | 313 | -0.66% | 780 | 0 | Village |
| Nebo | 8 | 269 | 277 | -0.37% | 620 | 0 | Village |
| Milton | 9 | 205 | 208 | 0% | 531 | 0 | Village |
| Kinderhook | 10 | 181 | 187 | -0.55% | 224 | 1 | Village |
| Baylis | 11 | 163 | 169 | -0.61% | 346 | 0 | Village |
| New Salem | 12 | 114 | 120 | -0.87% | 109 | 1 | Village |
| Pearl | 13 | 104 | 106 | 0% | 69 | 2 | Village |
| Detroit | 14 | 74 | 74 | 0% | 295 | 0 | Village |
| Florence | 15 | 16 | 18 | 0% | 58 | 0 | Village |
| Valley City | 16 | 15 | 14 | 0% | 56 | 0 | Village |
Pittsfield is the largest city in Pike County, with a population of 3,985.
Valley City is the smallest city in Pike County, with a population of 15.
There are 16 cities in Pike County, Illinois.