Los Fresnos United is located on FM 803 just south of Texas Highway 100 and houses all Los Fresnos CISD students in grades 9 and 10.
LFU opened in 2009 for students in Grade 9 only. Prior to 2009, freshmen students were enrolled at Los Fresnos High School. Additions were made to the school in 2014, 2015 and 2016, and the school added students in Grade 10 that year. Future additions are planned.
LFU is an extension of Los Fresnos High School. The campus houses about 1,600 students. The school mascot is Falcons like LFHS and the principal is Maria E. Pineda.