8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sealy | 1 | 7,734 | 6,826 | 2.4% | 660 | 12 | City |
| Bellville | 2 | 4,311 | 4,211 | 0.47% | 1,583 | 3 | City |
| Wallis | 3 | 1,376 | 1,296 | 1.18% | 920 | 1 | City |
| San Felipe | 4 | 724 | 688 | 0.98% | 87 | 8 | Town |
| Brazos Country | 5 | 528 | 516 | 0.38% | 270 | 2 | City |
| New Ulm | 6 | 455 | 318 | 7.06% | 85 | 5 | CDP |
| Industry | 7 | 296 | 266 | 2.07% | 277 | 1 | City |
| South Frydek | 8 | 226 | 210 | 1.35% | 128 | 2 | City |
Sealy is the largest city in Austin County, with a population of 7,734.
South Frydek is the smallest city in Austin County, with a population of 226.
There are 8 cities in Austin County, Texas.