Tiffin is a city located in Seneca County Ohio. It is also the county seat of Seneca County. With a 2020 population of 17,646, it is the 102nd largest city in Ohio and the 2054th largest city in the United States . Tiffin is currently growing at a rate of 0.18% annually but its population has decreased by -1.76% since the most recent census, which recorded a population of 17,963 in 2010. Tiffin reached it's highest population of 21,596 in 1970. Spanning over 7 miles, Tiffin has a population density of 2,569 people per square mile.
The average household income in Tiffin is $55,021 with a poverty rate of 13.57%. The median rental costs in recent years comes to $677 per month, and the median house value is $97,100. The median age in Tiffin is 37.2 years, 34.5 years for males, and 39.9 years for females.