| Place Name | San Marcos |
| Place Type | City |
| ZIP Code(s) | 78666 |
| County | Hays County Caldwell County |
| Area Code(s) | 512,737 |
| Timezone | Central Daylight Time (CDT) |
| Population (2022) | 46,131 |
| Population Growth Rate (2010-19) | 50.47% |
| Majority Ethnicity | White 58.75% |
| Metro/Micro Stats Area | Austin-Round Rock-Georgetown, TXSan Antonio-New Braunfels, TX |
| US Congressional District(s) | Texas 35thTexas 21st |
| State House Districts | 17,45 |
| State Senate Districts | 21,25 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 58.75% |
| African American | 5.57% |
| Hispanic | 0.34% |
| Asian | 2.1% |
| Native American | 0.07% |
| Hawaiin/Pacific Islander | 33.17% |