Gunn, who wrote and directed the first two installments of the Marvel Cinematic Universe sci-fi franchise, was reinstated as the director of the next film after several months of meetings with Disney studio officials, including Walt Disney Studios President Alan Horn.
The director, who penned a script for Guardians of the Galaxy Vol. 3 prior to his dismissal, was removed from the film in July after alt-right journalists unearthed decades-old social media posts in which Gunn made jokes about subjects including pedophilia and rape.
Gunn had apologized for the tweets years earlier, and apologized again when the jokes resurfaced. Horn was reportedly swayed by Gunn's apology and his conduct after his firing.
Marvel Studios has agreed to begin filming Guardians of the Galaxy Vol. 3 when Gunn has completed work on Suicide Squad 2 for Warner Bros. and Marvel's rival, DC.