Sir William Edmond Logan (1798-1875) was a noted 19th century Canadian geologist.

Logan was born in Montreal, Quebec on April 20, 1798. He started teaching himself geology in 1831, at the age of 33. His abilities as a geologist were noticed, and in 1842 he was asked to establish the Geological Survey of Canada.

Over his illustrious career he received 22 medals including the Legion of Honor from Emperor Napoleon III of France in 1855 and a knighthood from Queen Victoria of England in 1856.

He died on June 22, 1875, in Wales and was interred in the churchyard in the village of Cilgerran.

The highest mountain in Canada, Mount Logan, was named after him.