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1 September 2015 Last updated at 17:31 BST
Alister Colley, who has a studio in Pateley Bridge near Harrogate, said to hear he had won was "almost unbelievable".
The title means he has become the most sought-after and collected artist in the country.
Colley said creating the official picture for the Grand Depart had put him on "a whole new international platform".
He has now been asked to be official artist for next year's Grand Depart.
An artist who painted the official picture for the Tour de France's Grand Depart from Yorkshire in 2014 has won the accolade of Best-selling Published Artist 2015.