St. Marys, Ohio

St. Marys population, 2020 to 2024

St. Marys lost 25 residents from July 2020 to July 2024, a change of -0.3%. In the latest year it moved by -46. Among 254 Ohio places of 5,000 or more, that growth ranks 120th; the median place changed by -0.4%. The median place of 5,000+ in Ohio has 13,905 people, so St. Marys is 60% of it.

St. Marys covers 4.67 square miles of land and 0.03 of water, for 1,794 people per square mile of land. The median Ohio place of 5,000+ has 2,000, so St. Marys is less dense than the typical town.

What county St. Marys is in

All of St. Marys's residents live in Auglaize County, which had 45,922 residents in 2024. St. Marys holds 18.2% of the county's population. The shaded shape is on the map above; dots mark the eight nearest places.

ZIP codes in St. Marys

1 ZIP Code Tabulation Area (ZCTA) overlaps St. Marys by at least 10% of the ZCTA's or the city's land: 45885. ZCTAs are Census approximations of USPS ZIP code delivery areas. The list comes from the 2020 ZCTA to place relationship file, so a city that annexed land after 2020 may reach into ZIP codes not listed here.

Where St. Marys is

The Census internal point of St. Marys is at 40.547600, -84.392300. Columbus, the capital, is 83.8 miles ESE in a straight line. The nearest larger place is Celina, OH (10,945 people), 8.9 miles away. The nearest city of 100,000 or more is Dayton, OH, 53.7 miles away.

Daylight in St. Marys

At 40.55° N, St. Marys gets about 15 h 05 min of daylight around the June solstice and 9 h 16 min around the December solstice, a swing of 5 h 48 min. Figures are sunrise to sunset from the SunCalc model for June 21 and December 21, 2026.

Places near St. Marys

The eight nearest incorporated places of 1,000+ in Ohio, measured between internal points. The closest is New Bremen, 7.8 miles away, with 3,020 people.