Bruni was named for Antonio Mateo Bruni, who was born in Bozzi, Emilia-Romagna, Italy, in 1856. After his parents died when he was a young boy, he moved to San Antonio in 1872 to live with an uncle, then moved with his brother Luigi to Laredo five years later and opened a mercantile store. He married Consolacion Henry in 1879, and they had nine children. Bruni became involved in the sheep and cattle industry and was appointed Webb County tax assessor in 1882, later serving as a county commissioner and county treasurer. About 1881, the Texas Mexican Railroad built a station on one of his ranches, where he opened a commissary. When the first school in the area opened in 1886, the small settlement was called Bruniville, and a post office was established in 1900 with Moglia Lodovico as the first postmaster. In 1922, the Bruni Townsite Company, established by C. R. Cole and Dudley Tyng, purchased and surveyed over 150 acres about one quarter mile west of the existing school and post office site. Oil discovered in the area during the 1920s brought growth to Bruni, and commercial-grade uranium mining beginning in the 1970s provided another economic boost. In 1974, the Bruni, Torrecillas, and Aguilares school districts combined to form the Webb Consolidated Independent School District, and when the Mirando schools joined in 2005, the Bruni-based WCISD became the only education facilities operating outside of Laredo in Webb County.