Dai Vernon was a Canadian magician. His expert sleight-of-hand technique and extensive knowledge garnered him universal respect among fellow magicians. His influence was considerable in the magic world, and he was a mentor to numerous famous magicians. He lived out his last years at the Magic Castle

While performing, he often mentioned that he had learned his first trick from his father at age seven, adding that he had "wasted the first 6 years" of his life. His father was a government worker and an amateur magician. He studied mechanical engineering but by World War I he had moved to New York City.

Vernon first fell in love with magic when he was seven years old after his father took him to see a magic show. The first real magic book he ever owned was an early edition of perhaps the most famous card book of them all, The Expert at the Card Table, by S. W. Erdnase. By the time he was 13 he had memorized the contents of the book. He also had a famous encounter with another up-and-coming young magician from his town, Cliff Green, who asked Vernon, "What kind of magic do you do?" Vernon responded by asking the boy to name a card. Upon pulling a pack of cards from his pocket, Vernon turned over the top card of the deck to reveal the named card and replied to the speechless Green, "That's the kind of magic I do. What kind of magic do you do?"

As a young man, Vernon moved to New York where, in the back room of Clyde Powers' magic shop, he found favor among many of the great magicians of the era, including Dr. James William Elliott and Harry Kellar.

He began to use the first name "Dai" after a newspaper used the name in place of "David"; the paper actually was using the Welsh nickname for David. When Verner first moved to the United States, the male member of a popular ice-skating pair had the surname Vernon; Americans continually mistook Verner's last name to be the same as the popular ice skater, and eventually the magician became fed up with correcting people and simply adopted "Vernon" as well.

Due to his extraordinary knowledge of, and skill at, sleight of hand, Vernon has long been affectionately known as The Professor. Harry Houdini (who in his early years billed himself as "The King of Kards") often boasted that if he saw a card trick performed three times in a row he would be able to figure it out. Vernon then showed Houdini a trick, where he removed the top card of the deck and placed it in the middle, and then turned over the top card to again reveal the original card. Houdini watched Vernon do the trick seven times, each time insisting that Vernon "do it again". Finally Houdini's wife, and Vernon's friends said, "Face it Houdini, you're fooled." For years afterward, Vernon used the title The Man Who Fooled Houdini in his advertisements.