Having previously won the cup in 1924, Darren Crawford's Saturday League battlers just had too much for opponents Holme Rovers, who never really tested United keeper Lee Johnson.
Goals from skipper Cameron Dobson and James Pinder eased Hunmanby clear in the first half of the game at a blustery Queensgate, then they comfortably hung on to clinch the victory.
The gap between the sides could easily have been a good deal bigger, as Hunmanby dominated the first half with the wind at their backs.
After a tentative first 10 minutes, Hunmanby switched through the gears and forced Holme onto the back foot.
Ryan Baldry volleyed the first effort wide, before Pinder was presented with a pair of great chances, the second he managed to head wide from just four yards.
Frustration grew as Hunmanby twice put the ball in the back of the net, but both times they were ruled out for offside.
Pinder was punished first by the linesman's flag, then Phil Warnett's whipped effort from distance was chalked off, even though the referee's assistant initially failed to give the decision.
This only spurred Hunmanby on and they struck two killer blows right on the stroke of half-time.
Firstly Dobson was picked out just a yard or two from goal and he made no mistake with a powerful finish.
Then Pinder was rewarded for his attacking toil when he finished at the second attempt to make it 2-0.
Hunmanby were hit by a blow of their own when the second half got underway, as centre-back Chris Duley departed with a head injury, Dave Wedge taking his place.
Still reeling from this, Holme began to find a foothold, with Johnson saving well from Jamie Harrison and Johnny Dawson. Then Matt Wright sent a free-kick just over the bar.
But Hunmanby soon refound their attacking flair as Dobson drove a skidding strike just past the Holme post, before Warnett smashed high and wide after more good play from Pinder.
Holme had their chance to launch a late rally with 10 minutes remaining, when a swift move through the middle gave Nick Cage an opportunity. But bodies were put on the line and the ball was scrambled away.
The injury jinx struck once again in the closing stages, as sub Wedge trudged off with a broken nose to be replaced by player-boss Darren Crawford.
His experience, alongside the defensive brilliance of Leigh Franks, allowed Hunmanby to see out the closing moments, lift the silverware and start the celebrations.