Making his debut for the Queensland club in 2009, he has played 172 games with the club (to date) and was a member of the team that won the Cowboys' maiden Grand Final in 2015 against the Brisbane Broncos.
Throughout his long, illustrious career, Tamou would go on to earn honours for Australia and New South Wales, playing 12 tests for the Kangaroos and 14 games for the Blues between 2012-2016- the prime of his career.
“I jagged this contract and was pretty fortunate to get it,” Tamou previously told The Courier Mail.
“To be here with the boys and enjoy it for one last time is pretty special. I'm taking it all in."
The forward announced his retirement on Thursday night at half-time of the club's match against the Cronulla Sharks.
Speculation has previously suggested Tamou would likely be offered another season in Townsville. However, the decision to retire means the Palmerston North-born forward will hang up the boots with 307 games under his belt.
The forward has only made two appearances this season, with a third game where he never made it off the interchange bench for Todd Payten's side. His season came to a standstill earlier this season after sustaining a lisfranc injury in Round 4 against the Gold Coast Titans.
One of the best props in the game during his first stint with the Cowboys, Tamou was involved in the turnaround of the Panthers during his time at the foot of the mountains, helping the side to their first of three straight grand finals in 2020 before exiting for the Wests Tigers.
When he joined at the beginning of the season, fellow Cowboys forward Coen Hess was just one of many players that were happy to see him return back to the club after a seven-year absence.
“I have a past with Jimmy (Tamou) and I'm so glad to see him back. I've always seen him as a Cowboy and he really fits in among the group, so in my eyes, he's back where he belongs," Hess said.
“He's another old, experienced head. That helped us last year with 'Pet' (Hiku) and Chaddy (Townsend) bringing a lot of experience to the group and Jimmy is of that calibre of player as well."