Kyle Amor has left Wakefield Trinity Wildcats and signed a four-year deal at Super League rivals St Helens.
Irish international prop Amor, 26, has been snapped up by Saints for a transfer fee of £50,000.
Saints head coach Nathan Brown said: “Kyle is a young British prop forward who is already one of the best front rowers in Super League.
“He will add strength, size and dynamism to our pack and is a great long term recruit for the club.
Saints chairman Eamonn McManus added: “There was understandably a lot of competitive interest in Kyle and we are delighted to have secured him on a long term deal.
“He is another key addition to the squad which we are putting together for next season and beyond.
“There are many reasons to be excited and confident about the future.”