9 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portland | 1 | 20,804 | 20,408 | 0.38% | 1,710 | 12 | City |
| Ingleside | 2 | 10,288 | 9,623 | 1.31% | 609 | 17 | City |
| Aransas Pass | 3 | 8,838 | 8,355 | 1.1% | 670 | 13 | City |
| Sinton | 4 | 5,678 | 5,527 | 0.53% | 1,111 | 5 | City |
| Mathis | 5 | 4,283 | 4,327 | -0.21% | 1,292 | 3 | City |
| Taft | 6 | 2,960 | 2,802 | 1.06% | 1,774 | 2 | City |
| Odem | 7 | 2,299 | 2,262 | 0.31% | 1,805 | 1 | City |
| Gregory | 8 | 1,712 | 1,736 | -0.29% | 1,123 | 2 | City |
| Ingleside on the Bay | 9 | 600 | 608 | -0.33% | 2,055 | 0 | City |
Portland is the largest city in San Patricio County, with a population of 20,804.
Ingleside on the Bay is the smallest city in San Patricio County, with a population of 600.
There are 9 cities in San Patricio County, Texas.