The title was established in 2007 via a single elimination tournament billed as the "Torneo Campeón de Campeones,” or Champion of Champions Tournament, which effectively unified the International Wrestling Council (IWC) World Heavyweight Championship, the Grand Prix Championship Wrestling (GPCW) SUPER-X Monster Championship, the Mexican National Heavyweight Championship, and the Universal Wrestling Association (UWA) World Light Heavyweight Championship. The tournament field included the four reigning champions of the aforementioned titles as well as the four number one contenders to each respective championship. "El Mesías" Ricky Banderas, who entered the tournament as the IWC World Heavyweight Champion, became the inaugural AAA Mega Champion upon defeating the UWA World Light Heavyweight Champion entrant Chessman in the finals.
In 2011, the AAA Mega Champion and Total Nonstop Action Wrestling (TNA) founder Jeff Jarrett appeared with a redesigned version of the title in TNA program, Impact Wrestling, which was called simply Mexican Heavyweight Championship, due to AAA not sanctioning their championships to appear on TNA television.
The inaugural champion was El Mesías, who defeated Chessman at Verano de Escándalo on September 16, 2007 in Guadalajara, Jalisco. El Texano Jr.'s only reign is the longest in history at 735 days. The youngest champion is El Texano Jr., who won at the age of 28 years and 124 days. The shortest reigning champion was Electroshock, who held the title for 86 days from March 12, 2010 to June 6, 2010. El Mesías has held the title the most times with four championship reigns. The oldest champion is Dr. Wagner Jr., who won it at the age of 44 years and 298 days. The current champion is El Patrón Alberto, who is in his first reign. He defeated El Texano Jr. for the championship at Guerra de Titanes on December 7, 2014, in Zapopan, Jalisco.