The 23-year-old finished with a tournament-high 12 offloads and covered 249 yards with the ball in hand – more than any other scrum-half in the competition.
France fell woefully short of the title, with England triumphing over the points difference, but Dupont collected 46% of the vote for individual honor.
Dupont topped a list of six finalists that also included teammates Gregory Alldritt, Romain Ntamack, England duo Maro Itoje and Ben Youngs and Irishman CJ Stander.
“His talent has clearly transcended borders, with supporters from all six unions supporting him in large numbers,” said Six Nations Rugby General Manager Ben Morel.
“Winning this award at such a young age is a great achievement. Bravo Antoine! ”
England center Emily Scarratt was named the Championship’s first female Six Nations player after playing an influential role in her team’s Grand Slam campaign.