Barnes is set to be named the NBA rookies of the year.
Barnes was reported to have won the award by Shams Charania of The Athletic and Stadium.
Barnes won the voting point with 378-363, followed by Mobley and Cunningham.
Barnes was the fourth overall pick in the NBA draft, and he played a huge role in getting the Raptors into the playoffs.
Barnes emerged as a ball- stopping perimeter menace, with defensive brilliance being a hallmark of both Mobley and him.
Barnes was given the task of defending the Raptors best perimeter player despite the Raptors being loaded with defensive minded, rangy wings.
The Florida State product had an average of 15.3 points, 7.5 rebound and 3.5 assists. His vision as a passer and work as a secondary ball-handler were impressive.
The third pick in last June's draft, Mobley averaged 15 points, 8.3 rebound and 2.5 assists per game as a defensive centerpiece for the upstart Cavs. He was one of the most versatile rookies in recent memory because of his ability to defend at the rim and switch onto guards in pick-and-rolls.
You don't see a guy that understands the job that needs to be done at that age and that experience, and then go out and do it.
Had Cunningham come along a little faster in Detroit, he would have won the award. It was hard for voters to overlook his struggles in the first two months of the season as the Pistons finished with a 23-59 record.
In March, Cunningham averaged 22.9 points, 7.0 assists and 5.9 rebound while leading a surprisingly spry Pistons team.
It wasn't enough to make him a serious contender to Barnes.