Scholtz, 17, joined the Club at the age of seven and progressed through the Academy ranks before signing scholarship terms ahead of the 2022/23 campaign.
The Northern Ireland Under-19 international spent most of pre-season with the first-team squad and made his professional debut for MK Dons as a substitute in the opening-day victory over Wrexham.
Scholtz has totalled three senior appearances already this term, including a first senior start in the EFL Trophy win over Chelsea Under-21s at Stadium MK.
“I’m just really happy,” the young full-back told iFollow MK Dons after signing his first contract. “It is a surreal feeling but I am really grateful to everyone who has helped me reach this point.
“This is something I have worked really hard for, ever since I first trialled with the Club at Under-8s. There have been plenty of ups and downs but hopefully I can be proof that this dream, so long as you work hard and dedicate everything to your passion.
“It’s been a rollercoaster start to the season for me – training with the first-team, making my debut and then getting called up by Northern Ireland. I’m constantly chasing these moments of success and it’s just made me hungrier and more determined than ever.
“This is the end of the beginning for me and my career. I just want to push on now and hopefully contribute to a winning MK Dons team.”
Scholtz is the fourth Academy player to sign professional terms since the end of last season, following on from Joel Anker, Charlie Waller and Callum Tripp. Alongside them, as well as Ronnie Sandford and Brooklyn Ilunga, the Club now have six professionals currently under contract, who have progressed from the MK Dons Academy.
Head Coach Graham Alexander said: “Phoenix came in during pre-season because of an injury and he impressed right away with his attitude, his commitment and his determination. We also liked his character and his personality.
“He hasn’t just earned a professional contract off of a couple of months with the first team, though. This is a result of all of the hard work he has put in since he was eight years old, throughout his time in the Academy.
“Phoenix is someone who has all the important characteristics that a professional footballer should have - the challenge now is progressing on that and continuing to work hard every day to want to practice and get better.”
Alexander added: “The biggest hurdle for young players is overcoming the changes and moments that will happen in their life after signing their professional contract. This is just a small stepping stone in their career and it’s important Phoenix, and our other young pros, don’t lose sight of what got them to this point.”
Academy Manager Ben Smith also commented: “Everyone associated with the Academy is delighted and incredibly proud of Phoenix's achievements and signing his first professional contract.
“His enthusiasm and determination are leaving a positive impression on those around him and we hope this serves as rich encouragement for other young people in the Academy.”
Smith continued: “Both Phoenix and Callum have received great support from their scholar teammates and demonstrates the importance of the principles they are working towards.
“They still have a college programme to complete and, as staff, we will make sure they achieve the best possible grades before the end of the season. During that time, they will continue to have fun and enjoy the opportunities that are being presented to them.”