Grass Island is a Island located in Grenville, Ontario and has an elevation of 75 meters.

• Latitude: 44° 45' 47'' North   (decimal: 44.7630555)
• Longitude: 75° 25' 37'' West   (decimal: -75.4269444)
• Topography Feature Category: Island
• Geographical Feature: Island
• Canadian Province/Territory: Ontario
• Elevation: 75 meters
• Location: Grenville
• Atlas of Canada Locator Map: Grass Island
• GPS Coordinate Locator Map: Grass Island Lat/Long