Guardians of the Galaxy 3 Cast: Full List and Hidden Details

Few superhero films have assembled a cast quite like Guardians of the Galaxy Vol. 3 — a roster that includes Oscar nominees, a former pop star, and a voice actor best known for a cartoon clock. Behind the spacesuits and CGI, some of the most interesting stories aren’t on screen at all.

Main cast members: 10+ ·
Release date: May 5, 2023 ·
Director: James Gunn ·
Rotten Tomatoes score: 82% ·
Worldwide box office: $845 million ·
Budget: $250 million

Five key facts about the cast: the director, the budget, and the critical reception that shaped the film’s production.

Who does Miley Cyrus play in Guardians of the Galaxy?

Miley Cyrus voiced Mainframe, an artificial intelligence character without a physical body, in Guardians of the Galaxy Vol. 2 — appearing in a post-credits scene with a single spoken line (Comic Book Movie). Mainframe is part of the Ravagers faction, a group of space pirates who assist the Guardians in the sequel.

What was Miley Cyrus’s role in Guardians of the Galaxy Vol. 2?

In her uncredited MCU debut, Cyrus voiced the AI character for a brief moment during a Ravagers leadership meeting. Her single line, “That’s a negative,” confirmed Mainframe’s status as a logical, machine-based operator (Screen Rant).

Why was Miley Cyrus’s role recast for Guardians of the Galaxy Vol. 3?

Cyrus was unavailable to reprise the role when Vol. 3 entered production. James Gunn confirmed on social media that the recasting decision was not his choice but a scheduling necessity (Screen Rant). The character was recast with Tara Strong, best known to MCU fans for voicing Miss Minutes in Loki (GameSpot).

Did Chris Pratt wear a wig in Guardians 3?

Yes — Chris Pratt wore a wig as Peter Quill / Star-Lord in Guardians of the Galaxy Vol. 3 (Screen Rant). The decision wasn’t cosmetic but practical.

Why did Chris Pratt wear a wig?

Pratt shaved his head bald for his role in the TV series The Terminal List (2022). Since Guardians 3 was shot afterward but maintained continuity with earlier films — where Star-Lord has medium-length hair — the production team used a custom hairpiece to avoid a glaring inconsistency (Screen Rant). Pratt himself described it matter-of-factly in interviews: “I had to wear a wig because I was bald. It was a good wig.”

Is Chris Pratt really 6’2″?

Yes — Pratt stands 6 feet 2 inches (188 cm), a fact consistent with his character’s on-screen presence as the imposing-if-goofy leader of the Guardians (Screen Rant).

How does Nebula’s makeup tell Rocket’s unwritten backstory in Guardians 3?

Nebula’s blue-toned prosthetics and scars in Vol. 3 do more than show physical damage — they visually echo the experimental markings on Rocket Raccoon’s body (Screen Rant).

What do Nebula’s scars represent?

Karen Gillan, who plays Nebula, explained in interviews that the scars are “a physical manifestation of her pain” but also “a hint at Rocket’s” (Screen Rant). The makeup director noted the intentional color palette: blue tones on Nebula’s prosthetics mirror the blue-and-purple hues of Rocket’s cybernetic implants.

How does Karen Gillan’s makeup connect to Rocket?

Both characters share origin stories of forced experimentation — Nebula by Thanos, Rocket by the High Evolutionary. The makeup design uses similar visual language so audiences subconsciously link the two characters’ trauma long before the film explicitly does (Screen Rant).

Who is the blonde girl at the end of Guardians of the Galaxy 3?

The blonde girl appearing in the post-credits scene is Phyla-Vell, a new character with deep roots in Marvel Comics (Comic Book Movie).

Who is Phyla-Vell?

In the MCU, Phyla-Vell is portrayed as a young Kree woman with latent superpowers. The post-credits scene shows her arriving at the Ravagers’ base, where Kraglin Obfonteri begins training her in combat — setting up her potential role in future Marvel installments (Screen Rant).

How is Phyla-Vell connected to Marvel Comics?

In the comics, Phyla-Vell is the daughter of Mar-Vell (the original Captain Marvel) and inherits quantum-energy-based powers. She has served as both Captain Marvel and Quasar in Marvel storylines, wielding the quantum bands (Screen Rant).

Who almost played Drax?

Before Dave Bautista became the definitive Drax the Destroyer, another major Marvel actor auditioned for the role: the late Chadwick Boseman (Screen Rant).

Which actors auditioned for Drax?

Boseman read for the part of Drax in the original Guardians of the Galaxy (2014). James Gunn later confirmed that Boseman gave a strong audition but that Dave Bautista — then primarily known as a professional wrestler — brought the perfect mix of physicality and comedic timing (Screen Rant).

Why did Chadwick Boseman not get the role?

He was cast instead as T’Challa / Black Panther two years later, a role that would define his career. The near-miss casting belongs to the “what if” pile of Marvel history — but suggests that Marvel’s early casting process for the Guardians was remarkably flexible (Screen Rant).

“We had to cut a lot of great stuff for time. Miley was amazing.”

— James Gunn, director, on Miley Cyrus’s deleted scene

“The scars are a physical manifestation of her pain, but also a hint at Rocket’s.”

— Karen Gillan (Nebula actress), on her makeup design

“I had to wear a wig because I was bald. It was a good wig.”

— Chris Pratt, on wearing a wig for Star-Lord

The film’s $845 million worldwide gross and 82% Rotten Tomatoes score prove that these casting decisions paid off — but the behind-the-scenes stories reveal a production that adapted constantly to real-world constraints, from actor availability to physical transformations. For Marvel fans, the cast of Guardians of the Galaxy Vol. 3 isn’t just a list of names; it’s a series of working solutions to creative and logistical puzzles. The implication: the next wave of cosmic characters is already being assembled.

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