Grenfell Rock is a Shoal located in Thunder Bay, Ontario and has an elevation of 183 meters.

• Latitude: 48° 29' 34'' North   (decimal: 48.4927777)
• Longitude: 88° 20' 37'' West   (decimal: -88.3436111)
• Topography Feature Category: Shoal
• Geographical Feature: Rock
• Canadian Province/Territory: Ontario
• Elevation: 183 meters
• Location: Thunder Bay
• Atlas of Canada Locator Map: Grenfell Rock
• GPS Coordinate Locator Map: Grenfell Rock Lat/Long