The 23-year old Dutch striker has joined the Magpies on loan for the remainder of the season with an option to join permanently in the summer.
De Jong joined 'Gladbach from FC Twente in July 2012 when he was a summer transfer target for Newcastle but has struggled to make an impact in Germany.
The new Toon signing said in a statement: "Newcastle is a great club and I have a good feeling about it.
"I am very impressed with the stadium and training ground and have been made to feel very welcome by everyone I have met.
"It has been a tough season for me so far, but I am here to play games and want to be important for the team, and successful with goals and assists.
"I am really looking forward to playing for Newcastle."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball