Avondale, MO has a population of 392 and is the 20,978th largest city in the United States. The population density is 2,900 per sq mi which is 3256% higher than the Missouri average and 3100% higher than the national average. The median age in Avondale is 37 which is approximately 2% lower than the Missouri average of 38. In Avondale, 48% of the population over 15 years of age are married, 90% speak English and 5% speak Spanish. 65% of Avondale residents were born in Missouri, 29% were born out of state, 2% were born outside of the United States and 5% were foreign born.