La Vingt-Septième Lettre is a Island located in Baie-James; Jamésie, Quebec.

• Latitude: 54° 21' 40'' North   (decimal: 54.3612295)
• Longitude: 70° 22' 6'' West   (decimal: -70.3683224)
• Topography Feature Category: Island
• Geographical Feature: Île / Ile
• Canadian Province/Territory: Quebec
• Location: Baie-James; Jamésie
• Atlas of Canada Locator Map: La Vingt-Septième Lettre
• GPS Coordinate Locator Map: La Vingt-Septième Lettre Lat/Long