Steve Carell said that Despicable Me 3 may be his last film as the voice of Gru. However, Carell stated that if he was asked to do a cameo in any future Minion sequels, he happily would.
Agnes's voice actress Elsie Fisher from the first and second movies was replaced by Nev Scharrel due to Fisher getting too old for the role.
The country that Dru lives in and Gru originates from is the fictional European country of Freedonia. This is the same name as a similar fictional European country in the 1933 Marx brothers' movie Duck Soup.
At the talent show, the Minions sing in Minionese "I Am the Very Model of a Modern Major General" from The Pirates of Penzance by Gilbert and Sullivan.
Though Dr. Nafario can be seen in a flashback, he remains silent. This makes it the first Despicable Me film to not feature Russell Brand voicing said character.
Margo's shirt has The Grinch on it. This is a reference to Illumination's next film.
Jenny Slate's third Illumination Entertainment film after The Lorax (2012) and The Secret Life of Pets (2016).
This is the first Illumination Entertainment film to be produced in a 2.35:1 widescreen aspect ratio; all of that company's previous films were produced in 1.85:1.
Steve Carell, Miranda Cosgrove, Dana Gaier, and Pierre Coffin are the only actors to reprise their roles for all three films. However, along with said characters, Kristen Wiig is also one of the few actors to be in all three films as she voiced Miss Hattie from Despicable Me(2010).
In France, the voices for the twins Gru and Dru are performed by Gad Elmaleh and Arié Elmaleh who are brothers in real life.
Jenny Slate's character, Valerie da Vinci's hair and looks are a reference to Kellyanne Conway.
In the prison, minions collect valuables from the prisoners, one of them is Mr. Bean teddy.
In one scene in Gru's lair the Minions are standing in front of a big computer machine with a green screen. The screen is actually displaying the Page R (the music sequencer screen) from a Fairlight CMI synthesiser series II which cost around £30,000 when originally launched back in 1982. It is unclear from the brief appearance in the movie what is being played back on the screen.
The animated sequence at the first part of the end credits, in which Dru & Gru are trying to outdo one another, is a reference to the opening credits sequences of the classic Pink Panther movies.
This is the first film to have the Illumination Entertainment logo simply read "Illumination".
The second Illumination Entertainment film to be rated PG for action and rude humor by the MPAA, after Minions (2015).
When Dru reaches into the power supply of the robot, the mechanism he pulls out is remarkably similar to the flux capacitor from "Back to the Future".
The film has 5 Academy Award nominees: Steve Carell, Kristen Wiig, Trey Parker, Steve Coogan and Pierre Coffin
Balthazar Bratt's name is probably a reference to actor Benjamin Bratt who previously voiced the villain, El Macho, from the previous film Despicable Me 2 (2013).
This film will feature Balthazar Bratt as the new villain. Other villains in the Despicable Me franchise have been Vector, El Macho, and Scarlet Overkill. Voiced by Jason Segel, Benjamin Bratt, and Sandra Bullock respectively.
John Cena, Ty Burrell, Ed Helms, Ed O'Neill, Josh Gad, Bill Hader, Danny McBride, Steve Zahn, Andy Samberg, Ashton Kutcher, Will Forte, Bruce Willis and John Malkovich were all considered for the role of Balthazar Bratt.