The 18-year-old’s triumph marked his sixth televised ranking title of the year, a feat only previously achieved by Phil Taylor and Michael van Gerwen.
Littler had navigated a challenging route to the finale, beating Jeffrey de Graaf, Ross Smith, Ricardo Pietreczko and Chris Dobey before overcoming Gerwyn Price 11-8 in the semi-finals, hitting ten 180s and averaging 108.48.
Aspinall arrived at the showpiece in a confident mood after easing past Jermaine Wattimena 11-2, but was ultimately unable to derail the teenage darting prodigy.
In the final, Littler raced to a brutal 8-4 lead, only for Aspinall to respond with finishes of 87, 127 and 86 to close the gap to 9-8.
Littler hit back immediately with a 14-dart break and an 88 checkout on double six to secure the victory.
"It wasn’t easy to reach the final, but I’m proud to tick this one off the list... only two more to go," Littler said after his latest triumph.
"I played brilliantly throughout, and I’m glad I got the job done as we look ahead to the big one next month."
Aspinall nonetheless enjoyed a strong week, rising six places in the world rankings to No. 15. His run to the final included wins over Karel Sedlacek, Richard Veenstra, Danny Noppert and Josh Rock.
"This has been a fantastic tournament," said Aspinall. "I’m back in the top 16, which was a big target, and the support here in Minehead is always amazing.
"I’ve got to congratulate Luke -- he’s incredible and it’s been great to share the stage with him."
Van Veen holds off Greaves
Earlier in Minehead, Gian van Veen successfully defended his World Youth Championship title, beating Beau Greaves 6-3.
The 23-year-old, who recently claimed the European Championship, produced two 13-darters and a 118 checkout to secure the victory.
Van Veen becomes only the second player, after Dimitri Van den Bergh, to win successive World Youth titles.
Greaves mounted a brief comeback but was ultimately undone by missed doubles.
Results
World Youth Championship
Final
Gian van Veen 6-3 Beau Greaves
Players Championship Finals
Quarter-finals
Gerwyn Price 10-6 Daryl Gurney
Luke Littler 10-5 Chris Dobey
Nathan Aspinall 10-8 Josh Rock
Jermaine Wattimena 10-8 James Wade
Semi-finals
Luke Littler 11-8 Gerwyn Price
Nathan Aspinall 11-2 Jermaine Wattimena
Final
Luke Littler 11-8 Nathan Aspinall