Mathis is a city in San Patricio County, Texas, United States. The population was 5,034 at the 2000 census. In 1887 when the San Antonio and Aransas Pass Railroad was laying tracks across San Patricio County, Thomas H. Mathis got naming rights when he donated 300 acres for a townsite and school. Mathis could well afford 300 acres since he and his brother J. M. Mathis, held 37,000 acres in the vicinity. The brothers had dropped out of the Coleman, Mathis, Fulton Cattle Company in 1879. Thomas Mathis owned an additional 60,000 acres around Mathis and built a fence enclosing the town. As late as 1906 Mathis was enclosed and arriving and departing trains had to be let in and let out.
Mathis' success was partially fueled by residents of Lagarto moving to be near the railroad. The Mathis post office opened in 1890 and the towns first school was held in a private residence in 1893. Two years later a one-room school built and in 1913 a second railroad (The San Antonio, Uvalde and Gulf Pacific) arrived.
Cotton and corn crops were grown and ranching was an important part of the economy. During the 30s, winter vegetable crops were grown and both railroads maintained shipping sheds. Mathis incorporated in 1939.