Fostoria, OH has a population of 13,397 and is the 3,121st largest city in the United States. The population density is 1,776 per sq mi which is 590% higher than the Ohio average and 1861% higher than the national average. The median age in Fostoria is 38 which is approximately 2% lower than the Ohio average of 39. In Fostoria, 50% of the population over 15 years of age are married, 97% speak English and 3% speak Spanish. 86% of Fostoria residents were born in Ohio, 13% were born out of state, 0% were born outside of the United States and 1% were foreign born.