The CMLL World Middleweight Championship (Campeonato Mundial Peso Medio de CMLL in Spanish) is a professional wrestling world championship promoted by the Mexican Lucha Libre wrestling-based promotion Consejo Mundial de Lucha Libre (CMLL). As it is a professional wrestling championship, it is not won legitimately; it is instead won via a scripted ending to a match or awarded to a wrestler because of a storyline. The official definition of the middleweight weight class in Mexico is between 82 kg (181 lb) and 87 kg (192 lb), but is not always strictly enforced. Because Lucha Libre emphasizes the lower weight classes, this division is considered more important than the normally more prestigious heavyweight division of a promotion. All title matches take place under two out of three falls rules.
Blue Panther was officially recognized as the first champion in 1991, after winning a 16-man tournament. The championship's history was interrupted in 1992 with its only , when Blue Panther left CMLL to work for rival promotion Asistencia Asesoría y Administración (AAA). El Dandy defeated Negro Casas in a singles match to decide the new champion. Ángel de Oro is the current CMLL World Middleweight Champion, having defeated Dragón Rojo Jr. for the championship on March 25, 2017. He is the 18th overall champion and the 14th person to hold the championship. El Dandy has had the most reigns as champion, with three; he also has the shortest reign, at 63 days, although Ángel de Oro's current, ongoing reign is shorter at the moment. Dragón Rojo Jr.'s single championship reign is the longest reign, at 1,954 days.