The duel for the biggest prize on the board, in front of 3200 rowdy fans in fancy dress, ended in a crushing defeat for three-time winner Van Gerwen in his seventh final at North London's Alexandra Palace.
"I can't believe it. Honestly, I can't believe it," gasped Littler, who started throwing darts as a toddler, at a dream come true.
"We both played so well. I said in my interviews, I needed to get off to a quick start and that's what I did.
"Everyone dreams of lifting this trophy but you have to get through a tough field."
Littler took a cagey opening set, neither finalist on their A game, and then found his rhythm with two quick 180s to go 2-0 up as Van Gerwen grimaced in frustration.
Van Gerwen, who will walk away 200,000 pounds richer as runner-up, won the opening leg of the third set but it proved a false dawn as an implacable Littler then raced 4-0 clear with a bullseye finish.
The Dutch 35-year-old, who set the previous record for youngest world champion as a 24-year-old in 2014, showed he was still in the fight by taking the fifth set but the comeback then faltered.
Littler, hand steady and gaze unwavering, fired in quick back-to-back 180s to take the opening leg of the sixth and then banged in two more maximum scores to secure the set and forge 5-1 up.
Van Gerwen raised his game to pull back to 5-2 but Littler whitewashed the next set to restore his advantage to 6-2.
Another set to the Dutchman only postponed the inevitable as Littler romped through the final set to get his hands on the mighty Sid Waddell Trophy, with the pent-up emotion finally released.
"I come 4-0 behind and after that I didn't do myself justice but that's the way it is," Van Gerwen said.
"I sometimes say every 17 years a star gets born and he's one of them."
