Third Island is a Island located in Cassiar Land District, British Columbia and has an elevation of 669 meters.

• Latitude: 59° 34' North   (decimal: 59.5666999)
• Longitude: 133° 43' West   (decimal: -133.7167000)
• Topography Feature Category: Island
• Geographical Feature: Island
• Canadian Province/Territory: British Columbia
• Elevation: 669 meters
• Location: Cassiar Land District
• Atlas of Canada Locator Map: Third Island
• GPS Coordinate Locator Map: Third Island Lat/Long