Temata, 34, has been with the Broncos since 2005, when he signed from New Zealand Warriors, making 137 appearances in the capital.
Injuries restricted him to just nine appearances this term, and he will now move on to play in the French Elite One League.
He said: “It’s going to be a bit of a shock when I leave as after eight years it’s become a way of life.
“I’m looking forward to a bit of a change but I’ll be coming back and definitely keeping in touch with the lads here.”
Broncos head coach Tony Rea said: “Karl has been a terrific servant to the club and a tremendously popular guy. He’ll certainly be missed and we wish him all the best down in France.”