9 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Rio Rico | 1 | 22,068 | 19,948 | 0.95% | 350 | 63 | CDP |
| Nogales | 2 | 20,018 | 19,750 | 0.27% | 961 | 21 | City |
| Tubac | 3 | 1,421 | 1,223 | 1.07% | 131 | 11 | CDP |
| Patagonia | 4 | 795 | 800 | -0.13% | 617 | 1 | Town |
| Sonoita | 5 | 722 | 727 | -0.82% | 68 | 11 | CDP |
| Elgin | 6 | 171 | 168 | 0.59% | 29 | 6 | CDP |
| Kino Springs | 7 | 158 | 302 | 0.64% | 612 | 0 | CDP |
| Beyerville | 8 | 32 | 25 | -23.81% | 96 | 0 | CDP |
| Tumacacori-Carmen | 9 | 3 | 99 | -89.66% | 2 | 2 | CDP |
Rio Rico is the largest city in Santa Cruz County, with a population of 22,068.
Tumacacori-Carmen is the smallest city in Santa Cruz County, with a population of 3.
There are 9 cities in Santa Cruz County, Arizona.