St. Marys is a city located in Ohio. St. Marys has a 2020 population of 10,653. St. Marys is currently declining at a rate of -0.62% annually and its population has decreased by -3.08% since the most recent census, which recorded a population of 10,992 in 2010. St. Marys reached it's highest population of 10,992 in 2010.
The average household income in St. Marys is $69,099 with a poverty rate of 9.72%. The median rental costs in recent years comes to $762 per month, and the median house value is $130,600. The median age in St. Marys is 37.3 years, 37.9 years for males, and 36.8 years for females. For every 100 females there are 92.4 males.