Wheeler, 22, has scored 16 tries in 40 appearances for his hometown club since making his debut in 2008. He is an ever present this season, scoring two tries in Saints’ four Super League games so far.
He said: “Saints are my hometown club and I couldn’t imagine being anywhere else. There is fantastic competition for places in the side at the moment and I’m looking forward to establishing myself long term.”
Wheeler played in last season’s Grand Final defeat against Leeds, coming on off the bench.
Chairman Eamonn McManus said: “We have a fabulous crop of home-grown young players at Saints at the moment and Gary Wheeler is one of their best and brightest.
“It’s great news that he has committed himself to his hometown club.”