Reiss arrives from Hertha Berlin, where his last job was as U19 coach.
City’s Academy Director Thomas Kruecken told the club's website: “I am very pleased and excited to be able to confirm our coaching structure for the new season.
“This is part of our evolution and progression looking to the future and also illustrates that we are keen to promote from within and encourage a clear career progression and pathway.
“We have enjoyed great success in recent seasons, but we want to continue to look to develop and improve.
“Continuing Manchester City Academy’s development is vital, and these appointments leave us ideally equipped to meet the challenges of next season and beyond.”
Reiss success Ben Wilkinson, who has been promoted to the U21 post after Brian Barry-Murphy's departure last week.