Blanch, 30, reached a mutual agreement with the club to cut short his stay in Perpignan, after scoring 42 tries in 70 Super League games for the club.
He said: “The main reason for my departure is my family. I left Australia in 2005, so it has been a long time that I’m away from my family. And after nearly 10 years in Europe, I felt it was the right time to return to my homeland.
“The three seasons I spent with the Dragons are without a doubt the best of my career. I will never forget the people I met here, and I want to thank everyone, starting with my wife who has supported me over the past ten years. I was very fortunate and privileged to live my passion.”
Blanch first came to the UK with Castleford in 2006, before moving on to Widnes, where he scored 28 tries in 39 games.
He then spent three seasons with Wakefield, and moved to Catalan at the start of the 2011 season.