According to the announcement, the show will return in 2019. Rwo episodes left to air in Legion’s second season. The show recently saw its original 10-episode Season 2 order upped by one more to 11 episodes for the season.
“Legion has redefined the superhero drama and exceeded all expectations as the intensity and revelation build through the second season,” said President of Original Programming for FX Networks and FX Productions Eric Schrier. “We are incredibly proud of Noah Hawley’s achievement and are honored to continue the series as it pushes the boundaries of conventional television storytelling.”
Source: IGN.com Legion Renewed for Season 3