Guadalupe County Texas map

It sits directly east of San Antonio, on the seam between the Hill Country and the coastal plain. Hays County is north, Caldwell northeast, Gonzales southeast, Wilson south, Bexar southwest and Comal northwest. New Braunfels lies 13 miles west and spills across the line, San Marcos is 21 miles north, San Antonio 35 miles southwest and Austin 49 miles northeast.

The county was created in 1846 out of Bexar and Gonzales counties and takes its name from the Guadalupe River, which the Spanish named for Our Lady of Guadalupe. Being inside the San Antonio–New Braunfels metropolitan area, it is one of the faster-growing counties in the state: the 2024 Census estimate puts it at about 195,000, more than 22,000 above the 2020 count.

Five of the eleven incorporated places straddle a county line, which is what makes Guadalupe unusual: its two largest communities, Schertz and Cibolo, are both split — Schertz across the Bexar and Comal lines, Cibolo across the Bexar line — and neither is the county seat. New Braunfels, whose centre is in Comal County, has pushed more than 21,000 residents over the boundary. Marion, Santa Clara, New Berlin, Staples and Kingsbury are small farm towns strung along the older roads.

Seguin was founded in 1838 as Walnut Springs and renamed the following year for Juan Seguín, and it became a place where people built in concrete long before that was ordinary. A local physician, John E. Park, worked out a limecrete mix in the 1840s using gravel from the Guadalupe, and dozens of poured-in-place houses and outbuildings went up over the following decades. A good number survive, which gives the older streets a look no other Texas county seat has. The tradition has an outsized modern monument: a large concrete pecan sits on the Guadalupe County courthouse lawn, a nod to the pecan bottoms along the river.

Texas Lutheran University, a private liberal arts university, has its campus a few blocks from downtown. Seguin also carries a share of the county's manufacturing — the Caterpillar engine plant, Continental's plant and the Alamo Group's operations are among the employers along the I-10 corridor.

The Guadalupe River enters from Comal County and runs the length of the county southeast toward Gonzales, and the Guadalupe–Blanco River Authority operates a chain of small hydroelectric dams on it here. Lake Dunlap, Lake McQueeney, Meadow Lake and Lake Placid are the resulting flat-water stretches between New Braunfels and Seguin, each narrow and lined with houses, boat docks and 1930s-vintage dam structures. The spill gate at Lake Dunlap failed in 2019 and drained the lake, which put the age of the whole chain into public argument and led to a district being formed to rebuild the dams.

Cibolo Creek forms much of the southwestern boundary with Bexar and Wilson counties. On the far side of that line, just outside the county, Randolph Air Force Base has shaped the western end of Guadalupe for decades: the flight training pattern runs over Schertz and Cibolo, and the base is a major employer for people living on this side of the county line.