Mexicois a city in Audrain County, Missouri, United States. The population was 11,320 at the 2000 census. It is the county seat of Audrain County GR6.Citizens of Mexico, Missouri are known as "Mexicoans" and not "Mexicans".Mexico also hosts the annualMiss MissouriPageant; the winner goes on to represent the state of Missouri in the Miss America pageant.