Muenster is a city in Cooke County, Texas, United States, along U.S. Route 82. The population was 1,556 at the 2000 census.
In 1887 the Missouri-Kansas-Texas Railroad constructed a line from Gainesville to Henrietta that passed through the site that would become Muenster. The town was subsequently founded in 1889 by German Catholic settlers Carl and Emil Flusche, who invited other German Catholics to join them. The town was originally to be called Westphalia, but since the name Westphalia, Texas was already taken, Muenster was selected instead in honor of Münster, the capital of Westphalia, but these cities are not sister-cities.
Many residents still spoke German in day-to-day life up until the First World War, after which the language was no longer taught in the schools and steadily declined in use.