The Dutch legend has also outlined what his old club must do to catch current champions Chelsea.
United initially struggled this season as the Dutchman failed to find a formation and line-up that suited him, but have since rallied in the second half of the campaign.
That has saw them make it back into the top four and secure Champions League qualification, meaning the Red Devils have achieved what they were aiming for this season. Many are now expecting a title challenge next year, and Stam is a supporter of those claims.
"Louis van Gaal is a great builder of a team; he’s proven that in Munich and Barcelona," he said.
“In terms of next season, if he can bring in a couple of new players and carry on working with the youngsters, telling them what to do and showing them videos, he’s going to win the league I think. Hopefully next season.”
The former defender has also highlighted jut what his old side need to do in order to challenge champions Chelsea next year.
Jose Mourinho’s side have won the Premier League at a canter this season, proving to be not only the best defensively, but one of the best attacking outfits as well.
However, the second half of the season saw them change tact and become more defensively solid, sacrificing their attacking flair in the process, and Stam has called for United to try and mirror that mentality next year.
“Maybe United need to defend a bit better to win the title,” he added.
“Chelsea didn't play the most attacking football, but they got results, and I think that’s what you need as a team and a manager. If they keep playing attacking football and don’t concede as many goals, eventually you’ll get results and win the league as well."