Roby, 28, made his Saints debut in 2004 and has since made 280 appearances for Saints, scoring 73 tries.
Rivals Wigan will be the opposition for Roby’s testimonial, which will take place on January 31st at Langtree Park.
“I fully appreciate all your support, not just now, but over the past 10 years too.
“To play against Wigan, the current champions and our close enemies, is sure to be a tough match. Both teams will be at full strength and new signings will be on show.
“Let’s create a fantastic atmosphere at Langtree Park that will roll on throughout the season.”