Mount Vernon, OH has a population of 16,777 and is the 2,549th largest city in the United States. The population density is 1,758 per sq mi which is 583% higher than the Ohio average and 1841% higher than the national average. The median age in Mount Vernon is 36 which is approximately 9% lower than the Ohio average of 39. In Mount Vernon, 51% of the population over 15 years of age are married, 98% speak English and 1% speak Spanish. 75% of Mount Vernon residents were born in Ohio, 24% were born out of state, 1% were born outside of the United States and 1% were foreign born.