The winger joined Forest last year from Manchester United.
Berry has committed to Forest for another 12 months and he said: "I am buzzing to have signed a new deal and can’t wait for next season. This is a great opportunity to kick on and improve ahead of what should be an exciting season. It was great to be a part of the International Cup win, hopefully we can win another trophy next year.”
Chris McGuane, Head of Academy, also told Forest's website: “We are delighted for Adam that he will continue his development with us having been at the club for just over a year now.
“Adam is an exciting creative player who can play in a number of positions across the forward line and has the ability to create and score goals. He deserves to have this chance, and we look forward to seeing how he progresses next season.”