St. Mary's Cays is a Shoal located in Newfoundland and Labrador.

• Latitude: 46° 43' 00'' North   (decimal: 46.7166666)
• Longitude: 54° 13' 5'' West   (decimal: -54.2180555)
• Topography Feature Category: Shoal
• Geographical Feature: Rocks
• Canadian Province/Territory: Newfoundland and Labrador
• Atlas of Canada Locator Map: St. Mary's Cays
• GPS Coordinate Locator Map: St. Mary's Cays Lat/Long