Mexico is a city in Audrain County, Missouri, United States. The population was 11,543 at the 2010 census. It is the county seat of Audrain County. The Mexico Micropolitan Statistical Area consists of Audrain County. Mexico hosts the annual Miss Missouri Pageant; the winner goes on to represent the state of Missouri in the Miss America pageant.
Mexico is located at 39°9′57″N 91°53′5″W / 39.16583°N 91.88472°W / 39.16583; -91.88472 (39.165814, -91.884761). N.E. of the centre of the state, and about 110 m. N.W. of St Louis. According to the United States Census Bureau, the city has a total area of 11.7 square miles (30.3 km²), of which, 11.4 square miles (29.4 km²) of it is land and 0.3 square miles (0.9 km²) of it (2.90%) is water.
Mexico was laid out as "New Mexico" in 1836 and was a major stop for settlers heading to the Republic of Texas (thus the name New Mexico), and became the county seat under its present name in 1837. The word "New" was dropped after the Mexican-American War that saw Texas become a part of the United States.