19th October 2017, 18:04 | catalans
The 22-year-old son of dual-code England international Jason Robinson, who spent the last three months of the 2017 season on loan from the Warriors, has made his move to the south of France permanent by signing a two-year contract.
Dragons coach Steve McNamara said: "Lewis proved to be a tremendous signing for us on loan last season and we are now delighted to have made that a permanent deal.
"His commitment, desire and determination to help us maintain our Super League status was there for all to see and we look forward to seeing him progress further as a player with the Dragons over the next two years."
Tierney, who is currently in Australia with Scotland's World Cup squad, came through Wigan's academy and was a member of their Grand Final-winning team in 2016. He was also in the side that beat Cronulla in the 2017 World Club Challenge before losing his place.
Catalans chief executive Christophe Jouffret said: "Lewis is one of the satisfactions of the tough end of season we had to face.
"The young full-back brought determination, freshness and enthusiasm to our squad. I would like to thank the Wigan Warriors who have agreed to grant Lewis a release to join our club."