Seal Island (also known as Great Seal Island) is an island on the outermost extreme of Southwestern Nova Scotia, Canada, in the Municipality of the District of Argyle in Yarmouth County.[1] It is approximately 4.3 kilometres (2.7 mi) long and 0.8 kilometres (0.50 mi) wide and is surrounded on its east, south and west sides by dangerous shoals.[2] It is surrounded by the Atlantic Ocean and is the biggest of a group of five islands which extend north for 12 kilometres (7.5 mi).