Nick Helm beat better-known acts including Tim Vine and Sarah Millican to the award created by TV channel Dave.
He won for the joke: ''I needed a password eight characters long so I picked Snow White and the Seven Dwarves.''
But there was bad news for veteran entertainer Paul Daniels, who won the wooden spoon for the worst joke of the festival.
He won the dubious honour for his gag: ''I said to a fella 'Is there a B&Q in Henley?' He said 'No, there's an H, an E, an N an L and a Y'.''