The 25-year old, who can play in the centres and in the second-row, has agreed to a one-year deal with an option of a second year.
He rejoined Salford in 2014 before making a move to Championship side London.
The former England Under-17 international said he is very excited to join the Wildcats.
“I am very excited to have signed, its a great opportunity,” Walton said in a statement.
“I am looking forward to working with Brian Smith, he is a fantastic coach and I cannot wait to continue to grow as a player and learn from him.”
Wakefield coach Brian Smith said Walton has impressed with his enthusiasm.
“His rugby talents and strong physical attributes suggest that Jason will make a real contribution in this big opportunity for him,” Smith said in a statement.