Thomson Bay is a Bay located in Lanark, Ontario and has an elevation of 141 meters.

• Latitude: 45° 1' 42'' North   (decimal: 45.0283333)
• Longitude: 76° 18' 45'' West   (decimal: -76.3125000)
• Topography Feature Category: Bay
• Geographical Feature: Bay
• Canadian Province/Territory: Ontario
• Elevation: 141 meters
• Location: Lanark
• Atlas of Canada Locator Map: Thomson Bay
• GPS Coordinate Locator Map: Thomson Bay Lat/Long