Connor Smith was taking part in the first lap of the day’s starting race when he came off his quad bike and was hit by other riders, Il Messaggero reported.
Despite paramedics immediately being called to the scene, in the Cingoli area, they were unable to save the teenager.
A 27-year-old Italian, Filippo Rondinini, was also injured in the accident and was taken to hospital.
In a statement, Smith’s father thanked everyone who had tried to help and said his son “died doing what he loved”, the newspaper said.
A message posted on Quad Racing Scotland’s website said the organization was “deeply saddened and shocked to learn of the tragic loss of Connor Smith”.
Smith was described as a “huge inspiration to quad riders…[who] achieved so much in his short life, and had so much still to give”.