Wauseon, OH has a population of 7,059 and is the 5,144th largest city in the United States. The population density is 1,366 per sq mi which is 430% higher than the Ohio average and 1407% higher than the national average. The median age in Wauseon is 36 which is approximately 8% lower than the Ohio average of 39. In Wauseon, 55% of the population over 15 years of age are married, 89% speak English and 9% speak Spanish. 75% of Wauseon residents were born in Ohio, 22% were born out of state, 0% were born outside of the United States and 3% were foreign born.