The AAA Mega Championship is a professional wrestling world heavyweight championship in the Mexican Lucha Libre AAA Worldwide (AAA) promotion. Known officially in Spanish as the Mega Campeonato AAA, it is sometimes referred to in the English-language press as the "AAA World Heavyweight Championship". The title is the top championship of the AAA promotion. The current champion is Nic Nemeth, who is in his first reign. He defeated Alberto El Patrón at Triplemanía XXXII: Monterrey on April 27, 2024 in Monterrey, Mexico.

The Mexican National Heavyweight Championship is a Mexican Lucha Libre championship created and sanctioned by the Mexico City Boxing and Wrestling Commission. While the Commission sanctions the title, it does not promote the events in which the Championship is defended. From 1933 until the mid-1990s, Consejo Mundial de Lucha Libre (CMLL) controlled the Championship, since then AAA gained control of the championship, after the Commission granted them control of the championship. In 2006 the championship was abandoned and replaced by the AAA Mega Championship. In 2009 the championship became active again on the Mexican Independent circuit until 2013. CMLL brought the championship back in 2017. Since the championship is designated as a heavyweight title, the championship can only officially be competed for by wrestlers weighing at least 105 kg (231 lb). However, the regulation is not strictly adhered to.