The 26-year-old, a graduate of Borussia Dortmund's academy, has signed a three-year contract at Carrow Road.
"Marco is an all-rounder and a creative guy," head coach Daniel Farke told Norwich's official website.
"He started his career as a number 10 but last season played as a holding midfielder and in the left full-back position a lot."
Farke added: "He will give us many options and is at a good age so that will help us to be more flexible."
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Championship club Norwich City have signed VfL Bochum midfielder Marco Stiepermann for an undisclosed fee.