The film was directed by Pierre Coffin and Kyle Balda, co-directed by production and character designer Eric Guillon, and produced by Chris Meledandri and Janet Healy, from a screenplay by the writing team of Cinco Paul and Ken Daurio.

In the film, Gru teams up with his long-lost twin brother Dru to stop Balthazar Bratt, a former child actor of the 1980s, from destroying Hollywood after his show was canceled years ago.

When Gru refuses to return to being a supervillain, and with his assistant Dr. Nefario accidentally frozen in carbonite,[a] most of his Minions, led by Mel, abandon him to find new jobs.

Dru reveals to Gru that their dead father was a supervillain known as "the Bald Terror", whose villainous activities and technological advances are the real source of the family's wealth.

With his robot's laser powered by the diamond, Bratt terrorizes Hollywood, covering it in superpowered bubble gum in hopes of lifting the city into outer space.

Gru engages Bratt in a dance fight before stealing his weaponized keytar to defeat him, and send him float away in bubble gum just as AVL helicopters arrive in time.

[17] The production team intended to give each Despicable Me film its own "larger narrative positioning", allowing the expansion of the main characters' stories.

[15] In April 2016, it was reported that Steve Carell would reprise his role as Gru and also voice his twin brother Dru, and that Trey Parker was cast as Balthazar Bratt.

[7] In September 2016, it was announced that Miranda Cosgrove and Kristen Wiig would reprise their roles as Margo and Lucy Wilde, respectively, and that Nev Scharrel would replace Elsie Fisher as Agnes.

Physical copies contain The AVL Database, behind-the-scenes featurettes, character descriptions, a Freedonian map, a deleted scene, a "Doowit" sing-along version, Minion mugshots and posters, a short film The Secret Life of Kyle, and a "Yellow Light" music video.

[25][26] Deadline Hollywood calculated its net profit at $366.2 million, accounting for production budgets, marketing, talent participation, and other costs; box office grosses and home media revenues placed it third on their list of 2017's "Most Valuable Blockbusters".

"[42] Peter Debruge of Variety wrote, "Despicable Me 3 is unwieldy, but it mostly works, as co-directors Pierre Coffin (who also voices the Minions) and Kyle Balda never lose sight of the film's emotional center, packing the rest with as much humor as they can manage.

"[43] Alonso Duralde of TheWrap gave the film a mixed review, saying: "Ultimately, none of these flaws will matter to the throngs of little kids who have made the previous Despicable Me movies (and the superior Minions spin-off) into giant global hits.

"[44] Sandy Schaefer for Screen Rant gives the film a three stars out of five saying "Despicable Me 3 offers enough in the way of zany, irreverent entertainment (with a dose of heart) to please steadfast fans of the franchise.

"[45] Jordan Mintzer for The Hollywood Reporter gave the film a positive review saying "This rather clever, breakneck-paced cartoon gives fans exactly what they want: Like the new nemesis voiced by Trey Parker, it shoots multiple machine-gun bursts of bubblegum at the audience, asking them to chew and enjoy"[46] Peter Travers of Rolling Stone gave the film three stars out of four, saying "Pierre Coffin (who voices the Minions) and co-director Kyle Balda keep the plot spinning merrily.

"[47] Leah Greenblatt of Entertainment Weekly gave the film a 'B' grade, saying "What shines through is the visual wit and innate sweetness of the storytelling, and Carell's cackling, cueball-skulled misanthrope a (mostly) reformed scoundrel who can still have his cake, and arsenic too.

"[48] The Minions' nonsense pastiche of the "Major-General's Song" was termed "amusing" (in an otherwise negative review)[49] and "the film’s finest moment";[50] it was uploaded to YouTube by Illumination as a singalong challenge and had garnered more than 19 million views as of 2023.