The 27-year-old has only managed 26 appearances, just seven of them starts, during an injury-plagued two years in the north east.
De Jong has scored just twice during his time on Tyneside and will now return to Holland and link up with his brother Luuk, who also spent time on loan at St James' Park during the 2013/14 season, at PSV.
Siem de Jong told PSV's official website: "I am very happy to have signed for PSV."
On playing with his brother, he added: "I can't wait. I am fit and could join the squad for full training.
"I will try to find my rhythm the next few weeks. It's great to join a club that takes part in the UEFA Champions League and wants to retain the Dutch title.
"I am really grateful PSV have offered me this opportunity."
PSV have won their first three Eredivisie games but lie second behind Feyenoord on goal difference.