Mary Islet is a Island located in Parry Sound, Ontario and has an elevation of 178 meters.

• Latitude: 45° 22' 16'' North   (decimal: 45.3711111)
• Longitude: 80° 11' 41'' West   (decimal: -80.1947222)
• Topography Feature Category: Island
• Geographical Feature: Islet
• Canadian Province/Territory: Ontario
• Elevation: 178 meters
• Location: Parry Sound
• Atlas of Canada Locator Map: Mary Islet
• GPS Coordinate Locator Map: Mary Islet Lat/Long