To confirm the news the 51-year-old British actor posted pictures of himself with director Matthew Vaughn and co-star Julianne Moore on Twitter.
"Reunited with Matthew Vaughn," he captioned the picture.
The sequel reportedly sees Eggsy (Taron Egerton) and Merlin (Mark Strong) join forces with their American counterpart Statesman, after the Kingsman organization is wiped out by the film's villain.
"Kingsman: The Golden Circle" also stars Pedro Pascal and Halle Berry. It will release on June 16, 2017.