The film was officially announced at the 2014 San Diego Comic-Con International before the theatrical release of the first film, along with Gunn's return from the first film, with the title of the sequel revealed a year later in June 2015.

 The film began principal photography in February 2016 at Pinewood Atlanta Studios in Fayette County, Georgia, with many crew changes from the first film due to other commitments made by many of the previous film's crew. Filming concluded in June 2016. Gunn chose to set the sequel shortly after the first film to explore the character's new roles as the Guardians, and to follow the storyline of Quill's father established throughout the first film—Russell was confirmed in that role in July 2016, portraying Ego, a departure from Quill's comic father.

Guardians of the Galaxy Vol. 2 premiered in Tokyo on April 10, 2017 and is scheduled to be released in the United States on May 5, 2017, in 3D and IMAX 3D.

 A sequel, Guardians of the Galaxy Vol. 3, is scheduled to enter production with James Gunn returning to write and direct the film.

Meanwhile, Ayesha hires Yondu Udonta and his crew, who have been exiled from the greater Ravager community for child trafficking, to recapture the Guardians. They capture Rocket, but when Yondu shows reluctance to turn over Quill, his lieutenant Taserface leads a mutiny with help from Nebula. Taserface imprisons Rocket and Yondu aboard Yondu's ship and executes his loyalists while Nebula leaves to track down and kill Gamora, whom she blames for all the torture inflicted on her by their father, Thanos. While imprisoned, Rocket and Yondu bond and the latter expresses his disdain for Ego. Groot, together with Yondu loyalist Kraglin, frees Rocket and Yondu and they destroy the ship and its crew as they escape, though not before Taserface tips off the Sovereign fleet.

Ego explains that he is one of the god-like Celestials, and exists in the form of the planet on which they are standing. He assumed a human guise to travel the universe and interact with other species, eventually meeting and falling in love with Quill's mother Meredith. After Meredith's death, Ego paid Yondu to collect the young Quill, but Yondu never delivered the boy, and Ego had been searching for his son ever since. He teaches Quill to manipulate the Celestial power within the planet. Nebula arrives at Ego's planet and tries to kill Gamora, but fails and the pair reach an uneasy alliance when they discover caverns filled with skeletal remains. Ego reveals to Quill that in his travels to thousands of worlds, he planted seedlings upon thousands capable of terraforming them into new extensions of himself, but they could only be activated by the power of a second Celestial. To that end, he impregnated hundreds of women and hired Yondu to collect the children; they all failed to access the Celestial power, so Ego killed them, until he found Quill. Ego uses Quill to activate the seedlings, which begin to consume every world. Quill is hypnotized into helping Ego, but fights back after Ego reveals that he deliberately caused Meredith's death.