Remi Lupinski, 16, has joined the club on a two-year professional contract.
Lupinski is thrilled about his new opportunity and expressed his excitement in a statement.
"I'm speechless, it's amazing to sign for Arsenal," he said.
"I'm looking forward to playing for this great club, and I just can't wait to get started."
Ben Smith, MK Dons Academy Manager, praised Lupinski's achievements and praised his dedication and hard work.
"We are incredibly proud of Rem's progress, demonstrating his exceptional skill and commitment," Smith said.
"We look forward to seeing Rem continue to grow and develop, and we're excited about what the future holds for him."
