Flint is an unincorporated community in southwestern Smith County, Texas, United States. It lies along State F.M. 2493 south of the city of Tyler, the county seat of Smith County. Its elevation is 522feet (159m). Although Flint is unincorporated, it has a Post office, with the ZIP code of 75762. Flint is considered to be part of the humid subtropical region. The town was named for Robert P. Flynt, a local landowner but the post office began operations in 1887 under the spelling "Flint" when postmaster Charles B. Brown misspelled the name on application forms.