Mainsville is a Unincorporated area located in Grenville, Ontario and has an elevation of 85 meters.

• Latitude: 44° 49' 7'' North   (decimal: 44.8186111)
• Longitude: 75° 26' 7'' West   (decimal: -75.4352777)
• Topography Feature Category: Unincorporated area
• Geographical Feature: Dispersed Rural Community
• Canadian Province/Territory: Ontario
• Elevation: 85 meters
• Location: Grenville
• Atlas of Canada Locator Map: Mainsville
• GPS Coordinate Locator Map: Mainsville Lat/Long