Forster, 20, is currently on a dual-registration contract with Championship side Swinton and has signed a new two-year contract, while centre Jones has signed a three-year deal.
Acting Head Coach Mike Rush said: “Both Josh and Carl have worked hard since joining our Academy system and have progressed to the first team squad on the back of their dedication. They now need to continue their development and keep their feet on the ground.
“If they do that there’s no doubt they can have big futures in the game.”
Jones made his debut at Warrington earlier this season and has gone on to score four tries in eight appearances.
Forward Forster, who signed from Pilkington Recs, made his debut in the all English side that beat Harlequins last September, and has made three first team appearances for Saints this season.