There are 7 US Post Offices in Guadalupe County serving a total of 113,637 residents equating to 16,234 residents per post office. It's estimated that approximately 181,377 packages are handled across the 7 county post offices annually. Guadalupe County is a county located in the U.S. state of Texas. As of the 2010 census, its population was 131,533. The county seat is Seguin. The county was founded in 1846 and is named for the Guadalupe River. Guadalupe County is part of the San Antonio, TX Metropolitan Statistical Area."