City of St. Mary, Missouri

St. Mary is located at 37°52'34" North, 89°56'55" West (37.876153, -89.948811).

According to the United States Census Bureau, the city has a total area of 0.60 mi² (1.56 km²). 0.60 mi² (1.56 km²) of it is land and none of the area is covered by water.

St. Mary is located in the Central Standard Time (CST) timezone, GMT-06:00. It observes Daylight Saving Time (DST).