There are reports the deal will pay the 25-year-old right-wing $66.2 million, beginning in the 2014-15 season after his current three-year deal expires.
"Claude is a high-quality young man that over the past few years has blossomed into our best player and also one of the top players in the league," Flyers General Manager Paul Holmgren said in a statement. "We look forward to more and better things to come from Claude over the next number of years as we try to achieve our goal of becoming a championship team."
Giroux -- taken 22nd in the first round of the 2006 draft -- has 91 goals and 199 assists in 333 since breaking in with the Flyers for the 2007-08 season. He had 13 goals and 35 assists in 48 games last season.