Leon Pryce has signed a three-year contract with Catalans Dragons.
The 29-year-old full-back will move to the French side after his contract at St Helens expires at the end of the season.
"I have had a great time at Saints and have nothing but brilliant memories of the club and the team," Pryce said of the move.
"I would also like to thank the fans for their support. They have been nothing but top class in my time at the Saints."
The former Great Britain Lion marks the Dragons' first British signing since they joined the Super League five years ago.
"This is one of our biggest recruits in six years and is a great honour for the club. The signing is recognition that six years of hard work have gained us the trust of major players like Leon Pryce," said club chairman Bernard Guasch.
"His arrival, along with that of Louis Anderson, should allow us to have greater ambitions, to aim even higher next season."
Pryce joined Saints from Bradford Bulls in 2006.