20th November 2017, 21:28 | catalans
The 22-year-old centre or second rower, who won his 10th cap in France's 36-6 defeat by England at the World Cup, is one that got away from the French Super League club.
Jullien started his rugby in Avignon and played in Australia for the Wynnum-Manly Seagulls club in Brisbane before joining Warrington ahead of the 2016 season.
Catalans coach Steve McNamara said: "Benjamin is exactly the type of player and person that the future of our club will be built on.
"His honest, hard-working and professional approach is what the Catalans club was founded upon.
"Every decision we make both in recruitment and retention will be based upon these values. Benjamin had an outstanding breakthrough season in 2017 with Warrington and his decision to join us is great for our organisation."
Jullien had 12 months left on his contract with Warrington, who agreed to release him for an undisclosed fee.
Wolves chief executive Karl Fitzpatrick said: "Ben and his representative explained that he did not wish to return to Warrington as he needed to be closer to his family.
🇫🇷 Benjamin Jullien sera un Dragon en 2018 !!— Dragons Catalans (@DragonsOfficiel) November 20, 2017
🇬🇧 Benjamin Jullien will be a Dragon in 2018 !!
"Although we discussed a number of options, Ben simply wanted to return to France. We respect Ben's decision and subsequently agreed a transfer fee with Catalan. We wish Ben all the best at his new club."
Julien, who made 33 appearances in Betfred Super League for the Wolves, said: "I'm happy that Warrington and the Dragons have reached to find an agreement to allow me to join the club.
"I'm grateful for everything Warrington have done for me but I wanted to come back to France to be close to my family. I'm now looking forward to joining my new club and to work with Steve McNamara."