The Canadian forward, who played for Tigers in the 2016/17 EPL-winning team before going to train as a firefighter in his homeland, returned to Shropshire in October.
He is a fans’ favourite but the 6ft 5in forward is calling time on his playing career.
“This is the hardest decision I have ever had to make,” Clarkson said. “I know how hard Tommy (Tom Watkins) worked to get me here and the investments from the sponsors.
“But this has been a tough year mentally and physically and I made a decision earlier in the season that if I got a job offer back home I would take it, and that is what has happened.
“When I chose to come back and play, away from my family, I only wanted to come to Telford.
“Other teams in the league and other countries were options but I only wanted to come back to play with this group, fans and sponsors.
“It’s been a privilege to wear that Tigers jersey and to compete with this group for another year.
“But it’s time to finally start my second career back home with my family. Thanks to all the fans, sponsors and team-mates for everything.”
Clarkson’s last home game will be against Blackburn Hawks on Saturday, with his final fixture 24 hours later at Nottingham.
Head Coach and general manager Tom Watkins said: “
It certainly came as a shock and is a blow for the team which leaves a big a hole. But as a team we will come together to fill that gap.”