Seguin ( /səɡiːn/) is a city in Guadalupe County, Texas, in the United States. It is part of the San Antonio-New Braunfels Metropolitan Statistical Area. As of the 2000 census, the city population was 22,011; the July 1, 2009 Census estimate, however, showed the population had increased to 26,842. It is the county seat of Guadalupe County. Seguin was a region once inhabited by the native Indians of Texas. Tonkawa's had predominantly lived in Seguin, camping around the Guadalupe River and other streams in the area . Eventually Spanish, Mexican, and Anglo settlements were founded in the location that would become Seguin.