Schultz, who requested a shock move to the Magpies on day one of the trade period, will wear the black and white next season after the Dockers accepted pick 34 and a future first-round pick from the Pies.
The 25-year-old was drafted with pick 57 in the 2018 national draft from Williamstown VFL and has kicked 101 goals in 90 games for Fremantle.
“I’d like to thank Fremantle for my time at the club and for coming to an arrangement with Collingwood,” Schultz said.
“The Dockers gave me my first football opportunity, and I will be forever grateful for my time there. I would not be the player I am today without the support of the football staff and players.
“Family is important to me and is one of the reasons I have decided to make the move back to Victoria.
“There is something special about the Pies — they have experienced ultimate success — and this is something I hope to one day be a part of. I am excited to pull on the black and white stripes next year.”
Schultz has kicked 63 goals over the past two seasons and was the top-ranked player at the Dockers for scoreboard impact, leading to fifth- and sixth-placed finishes in the 2022 and 2023 Fremantle best-and-fairest vote counts respectively.
Fremantle head of player personnel David Walls said the club was disappointed with the trade, with Schultz a valuable commodity for the Dockers.
“It’s obviously disappointing to see Lachie depart after seeing him arrive at pick 57 in 2018 and develop into the player he is today,” Walls said.
“We know Lachie loved his time at Fremantle, and we were understanding of his reasons for returning to Victoria.”