The United Mexican States is bordered to the north by the United States; to the east by the Gulf of Mexico, to the south and west by the North Pacific Ocean; and to the southeast by Guatemala, Belize and the Caribbean Sea. Covering almost 2 million square kilometres, Mexico is the 6th largest country in America by total area and 15th largest in the world. With a population of about 108 million, it is most populous Spanish-speaking country in the world and its capital, Mexico City (Ciudad de México), is one of the most populous cities on Earth.

The word Mexico may have derived from the Nahua Aztec tribe word Mexitl - a secret name for the god of war, in which case Mexico means 'Place where Mexitl lives'. Another suggestion is that it comes from the words metztli (moon), xictli (centre), meaning 'Place at the centre of the Lake Moon', in reference to Lake Texcoco at the middle of which Mexico City was built.