The CMLL World Light Heavyweight Championship (Campeonato Mundial Semi Completo de CMLL in Spanish) is a singles professional wrestling world championship promoted by Consejo Mundial de Lucha Libre (CMLL) since 1991. 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 Light Heavyweight weight class in Mexico is between 92 kg (203 lb) and 97 kg (214 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.
The first champion to be recognized by CMLL was Jerry Estrada, who defeated Pierroth Jr. in the finals of a 16-man tournament that took place between September 15 and September 26, 1991. La Máscara is the current CMLL World Light Heavyweight Champion in his first reign, after defeating Ángel de Oro on April 8, 2016. Overall, there have been fifteen reigns shared among fourteen wrestlers. As of June 26, 2009, Dr. Wagner Jr. and Atlantis are the only two wrestlers to have held the title twice; Dr. Wagner Jr. is listed as an unofficial three-time champion, but he is not recognized as such by CMLL. La Máscara's ongoing reign is currently the shortest reign, followed by Jerry Estrada's reign, at 175 days, while Último Guerrero has held it for the longest period, at 1,309 days. Aquarius' unofficial title reign is the shortest on record, 8 days, but is not acknowledged by CMLL.