Wilson's arrival gives Perth another option on the wing ahead of its inaugural NRL season.
He is the Bears' 29th player and could challenge Englishman Harry Newman for a wing place.
Sean Russell, Gehamat Shibasaki and Nick Meaney are expected to fill other back-five positions, while Apa Twidle and Mason Barber are competing for fullback.
The 26-year-old Sunshine Coast junior began his NRL career at Canterbury in 2023, scoring six tries in 11 games.
Wilson joined Manly in 2026; the Sea Eagles confirmed his departure weeks ago, and he has 30 NRL appearances.
He will start Perth's pre-season training in mid-November.
"It's a pretty special opportunity to be part of a club's first year in the NRL, and I can't wait to get to Perth and get to work," Wilson said.
Coach Mal Meninga praised Wilson's size, speed, finishing ability and versatility across the backline.
Perth could begin its NRL campaign against South Sydney, with the 2027 draw scheduled for release on November 16.