The 30-year-old will join the club at the end of the current campaign and take up a two-year deal which could signal the move of Brad Drew to rivals Castleford.
Coach John Kear said: “After much speculation, the club has decided to confirm Terry’s capture.
“This is another pointer to the fact that Wakefield Trinity Wildcats is a developing and improving club. I am very happy that a player of the calibre of Terry Newton has decided to join us.
“I feel that Terry’s experience and ability will allow the team to once again improve in 2010 and beyond.”
Newton began his career at Leeds Rhinos before moving to Wigan where he picked up the majority of his international honours. In 2005, he switched from the Warriors to the Bradford Bulls in a part-exchange deal with Mick Higham.
“I’m very much looking forward to joining the Wildcats,” said Newton.
“I had the opportunity to go to a number of other clubs but I wanted to come to Wakefield as I have been very impressed with how they have performed this season and the current set up.
“It has been a fantastic atmosphere whenever I have played against Wakefield and I just can’t wait to get involved and pull on the Wildcats shirt.”