Porphyry Island is a Island located in Thunder Bay, Ontario and has an elevation of 183 meters.

• Latitude: 48° 21' 2'' North   (decimal: 48.3505555)
• Longitude: 88° 38' 9'' West   (decimal: -88.6358333)
• Topography Feature Category: Island
• Geographical Feature: Island
• Canadian Province/Territory: Ontario
• Elevation: 183 meters
• Location: Thunder Bay
• Atlas of Canada Locator Map: Porphyry Island
• GPS Coordinate Locator Map: Porphyry Island Lat/Long