Baitieri, currently sidelined through injury, has made 252 appearances since joining the Super League club from Sydney Roosters in 2011, and was in the team that made history by winning the Challenge Cup at Wembley in 2018.
Only Remi Casty and Greg Mounis have made more appearances for the French club, who entered Super League in 2006.
Baitieri said: “After 11 seasons at the club, I can confirm I will be leaving the Dragons at the end of the season.
“I would like to thank Bernard Guasch and the Dragons’ board of directors for their support and trust since I have arrived in the south of France.
“I would also like to thank all my team-mates past and present that I have had the pleasure to play alongside over the years as well as the coaches, staff and everyone involved in the administration side at the club for some unforgettable memories.
“The season is not over, there is plenty of work still to be done to bring a trophy to Perpignan and we are working the best we can to put ourselves in the best position to do so.”
Catalans coach Steve McNamara said: “Jason has given outstanding service to the club over more than 250 games.
“He has contributed immensely to the progression of the club from its infancy to its current position and he will be missed by us all.
“We respect his decision and wish him and his family well with their future plans.”
Baitieri won 22 caps for France on the international stage and represented them in the 2017 World Cup.