He was presented with the trophy by Harry Aikines-Aryeetey – a former sprinter who won the award in 2005 – and ex-rugby union player Jodie Ounsley, both of whom are stars of the BBC television show Gladiators.
Skateboarder Sky Brown, 16, and Para-swimmer William Ellard, 18, were also shortlisted for the award.
Littler became a household name at the start of 2024 by reaching the World Championship final aged just 16 years and 347 days.
That achievement was just the start of a trophy-laden year, with Littler winning the Premier League Darts, Grand Slam and World Series of Darts Finals among his haul of titles.
Littler has gone from 164th to fourth in the world rankings and earned more than £1m in prize money in 2024.
The judging panel for Young Sports Personality of the Year included Paralympic gold medallist Sammi Kinghorn, Olympic silver medal-winning BMX freestyler Keiran Reilly, television presenter Qasa Alom and Radio 1 DJ Jeremiah Asiamah, as well as representatives from the Youth Sport Trust, Blue Peter and BBC Sport.