David Atherton, an international health adviser who now lives in London, has been one of the 13 contestants competing in the Channel 4 programme's tenth series.
His showstopper, a picnic-themed host of cakes, was described by host Paul Hollywood as "exceptional" on tonight's season finale.
"You've come up with something that is very, very clever," he said.
David also won star baker for the first time in the series for his impressive souffles.
After the announcement that he won, he said: "I've watched this since the second series so for nine years I've been daydreaming about Bake Off.
"Honestly, it was not in my mind I could win this."
Co-contestants Steph and Alice were primed to take the top spot after having more success than David in previous episodes.
But Hollywood told him he "smashed it", adding: "He's come from nothing and then won the whole thing - it's priceless."
David add: "It feels so good, it's been weeks and weeks of intensity, and then fatigue and intensity. To finish it off with this, it's the best feeling in the world."
He goes through to next week's final along with last night's star baker Alice, and Steph.
David was first inspired to bake by his mum Julie, who still lives in Whitby with his dad Richard and was an avid baker when David was growing up.
His interest in baking grew after a work trip to Malawi, where he learned to build an oven out of an oil drum and invented a cake that could steam over a village fire.
He made a Whitby-inspired fish pie during pastry week.
David, 36, shared a similar sentiment, previously said he never thought I'd make it to the final.
"It seemed like everyone else wanted it more, but maybe that was to my advantage because I was so happy to have just made it on the show, I was chilled," he said.
A segment at the end of the show told viewers that David had moved in with his boyfriend Nik since filming of the GBBO took place.