After seeing his time at Kogarah come to an end at the cessation of this season, Gosiewski is now set to join his fourth club since 2017.
The 28-year-old began his NRL career with South Sydney in 2016, playing six games in two seasons at the burrow before venturing to Manly.
Gosiewski has played the majority of his career at Brookvale, including a 19-game season with the club in 2019.
After 46 games for the Sea Eagles, Gosiewski departed Manly and would sign with St George Illawarra for 2022.
His most recent campaign tallied just four appearances, with the Murwillumbah-born forward again finding himself under a cloud of uncertainty after parting with the Saints.
Nevertheless, in the midst of this off-season, Gosiewski has joined his fourth club in a move to Townsville from next year.
“We were in the market for an experienced back-rower, who could play in the middle if needed and Jack certainly fits that need,” Cowboys General Manager of Football Micheal Luck said in a club statement.
“He will add significant depth to our forward pack and we expect him not only to compete for a spot, but also to push the players ahead of him.”
Gosiewski is the Cowboys' sole addition for next season, while the likes of Daejarn Asi (released), Ben Condon (Manly Sea Eagles), Tom Gilbert (The Dolphins), Connelly Lemuelu (The Dolphins) and Hamiso Tabuai-Fidow (The Dolphins) have departed the club.