San Marcos city, Texas
Official LSAD Designation: San Marcos city • Census GEOID: 4865600
• Caldwell County / Guadalupe County / Hays County
San Marcos city is an incorporated city in Caldwell County, Guadalupe County, Hays County, Texas. According to official records from the Census (2025), San Marcos city had an estimated population of 77,830 residents. Official Census Bureau geographic records classify this community under LSAD designation San Marcos city (GEOID 4865600).
Local Government Administration U.S. Census Bureau GMAF
City Of San Marcos
Municipal
Official Title:
Mayor
Address:
630 E HOPKINS ST, SAN MARCOS TX 78666-6300
County Of Caldwell
County
Official Title:
County Judge
Address:
110 S MAIN ST, RM 201, LOCKHART TX 78644-2701
Civic & Statistical Snapshot
| Category | Estimate | Survey Period / Source |
|---|---|---|
| Total Population | 77,830 | 2025 |
| Median Household Income | $51,281 | 2020-2024 |
| Median Home Value | $310,400 | 2020-2024 |
| Land Area | 40.49 sq mi | Gazetteer (2026) |
| Civic & Public Services | Hospitals, Libraries, Colleges | CMS / IMLS / IPEDS |
| Schools & Districts | NCES Directory Listings | Provided by k12guides.com |
| Nearby Airports | Landing Facilities | Provided by airport-data.com |
| Climate & Weather | NOAA 30-Year Normals | 1991–2020 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).