The powerful prop has been named in the Giants squad for Saturday's home Super League clash against Wigan (6.05).
It's the first time the no-nonsense Aussie, pictured right, has been in contention since undergoing a knee reconstruction at the end of last season.
The timing of Gannon's return couldn't be better, with several players nursing knocks in the wake of the tough Easter programme against Hull and Bradford.
The initial plan was for the front-rower to play in a Senior Academy clash to get some match fitness under his belt.
But due to the knocks being carried by his teammates and with the way Gannon has been training, a return in this weekend's top-flight fixture has become increasingly likely.
"Jim is fit and raring to go," said head coach Jon Sharp. "It's been a frustrating six months for him sitting on the sidelines and he looks as if he's ready to take that frustration out on his opponents."
* A reminder to all Giants fans that tickets for a week on Saturday's away clash at Harlequins will remain on sale only until 5pm tomorrow.