Mexico is a major economic power in Latin America and an important mineral producer in the world. Based on data obtained from Mexico global-scale geochemical mapping using 287 deep soil (C layer) samples, this paper produced a C-layer copper geochemical map with a scale of 1∶8000000. The geochemical background and spatial distribution characteristics of copper in soil were studied from a global-scale perspective, and the major copper geochemical anomalies of Mexico were delineated. The main findings are: (1) the copper content in soils of Mexico ranged from 3.6 to 129.0 μg/g, with the mean and median values being 20.3 and 15.9 μg/g, respectively, and the background value being 15.6 μg/g. The Chiapas Plateau and the Southern Madre Island Arc had significantly higher median copper content than other tectonic units, and had the highest background copper value in the whole country. (2) The geochemical map showed uneven distribution of copper content in soil, with the general trend of high in the south, low in the north, and high in the west, low in the east. (3) The geochemical map identified ten copper geochemical anomalies, eight of which reached mega-province scale and two reached province scale. Based on the fit between copper geochemical information and existing mineral deposits, it is considered that the Sierra Madre del Sur and Chiapas Mountains in southern Mexico are important prospective areas for copper in Mexico.