The United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Sites are places of importance to cultural or natural heritage as described in the UNESCO World Heritage Convention, established in 1972. Cultural heritage consists of monuments (such as architectural works, monumental sculptures, or inscriptions), groups of buildings, and sites (including archaeological sites). Natural features (consisting of physical and biological formations), geological and physiographical formations (including habitats of threatened species of animals and plants), and natural sites which are important from the point of view of science, conservation or natural beauty, are defined as natural heritage. Mexico accepted the convention on 23 February 1984, making its historical sites eligible for inclusion on the list. Mexico has 35 sites on the list (the highest number of sites in the Americas) and a further 24 tentative sites. Mexico's first six sites, Sian Ka'an, Pre-Hispanic City and National Park of Palenque, Historic Centre of Mexico City and Xochimilco, Pre-Hispanic City of Teotihuacan, Historic Centre of Oaxaca and Archaeological site of Monte Albán, and Historic Centre of Puebla, were inscribed on the list at the 11th Session of the World Heritage Committee, held at UNESCO headquarters in Paris, France in 1987. The most recent inscription was the Tehuacán-Cuicatlán Valley, listed in 2018. There are 27 cultural, six natural, and two sites listed both for their cultural and natural significance. The Islands and Protected Areas of the Gulf of California site has been listed as endangered because of the imminent extinction of the vaquita, an endemic porpoise in the gulf.

World Heritage Sites

UNESCO lists sites under ten criteria; each entry must meet at least one of the criteria. Criteria i through vi are cultural, and vii through x are natural. {{Legend|#FFE6BD| In danger|outline=silver}}

Tentative list

In addition to sites inscribed on the World Heritage list, member states can maintain a list of tentative sites that they may consider for nomination. Nominations for the World Heritage list are only accepted if the site was previously listed on the tentative list. As of 2023, Mexico maintains twenty-three properties on its tentative list: