San Benito is a city in Cameron County, in the US state of Texas, United States. Its population was 24,861 at the 2020 census. On April 3, 2007, San Benito celebrated the 100th anniversary of its naming. The post office was named "Diaz" from April to May 1907. The San Benito Museum, Freddy Fender Museum, and Conjunto Music Museum opened in the same building on November 17, 2007.