Adam Swift will leave St Helens at the end of the current season to take up a contract with Hull FC.
Winger Swift has featured 126 times for his home town club since making his debut in 2012.
He has crossed the whitewash 86 times and was part of the Grand Final winning team that defeated Wigan at Old Trafford in 2014.
Swift burst on to the scene scoring a hat-trick of tries in only his second appearance and went onto be an integral part of the first team following the club’s move to the Totally Wicked Stadium.
He followed up that Grand Final win with a 22-try campaign in 2015 and in his Saints career has incredibly scored four tries in a match on three separate occasions.
Adam said: “It was a really tough decision to make being a home grown lad and moving away, but it’s the right decision for me and I’m really looking forward to it and to the challenge ahead.”
Saints' head coach Justin Holbrook said: “I can completely understand Adam’s decision to move on, he is a Super League player and has unfortunately had limited opportunities in his
position in recent times.
"Selfishly, I would have loved to have kept him, he is a great guy and it’s a shame that someone with such close affinity to the club will be moving on.I wish him all the best for the future.”
Chairman Eamonn McManus added: “It will be sad to see Adam leave his home town club where he has contributed so much to our success over the years in addition to being an incredibly popular member of our squad.
''That said, we fully understand and appreciate his wish to play regular first team rugby with a top club, which Hull FC certainly is.
''We all wish him and his family more than well.”