- B-Team Sequel: Director Barry Sonnenfeld and actors Tommy Lee Jones and Will Smith did not return.
- Celebrity Voice Actor: In the Japanese dub Agent M is voiced by the actress and model Mio Imada, better known for playing Airi Maya in the live-action adaptation of Boys over Flowers.
- Cultural Translation: The film features a scene where M stares at an alien-monitoring screen that features a differing cameo of a media celebrity based on the country the movie screens in, to which High T claims "It's never who you think it is".
- Fake Brit: The Australian Chris Hemsworth plays the British Agent H.
- Release Date Change: Previously set for a May 17, 2019 release. It was pushed to June 14, 2019.
- Role Reprisal:
- Sequel Gap: The film was released seven years after the last installment, Men in Black 3.
- Those Two Actors: The pairing of Chris Hemsworth and Tessa Thompson worked so well in Thor: Ragnarok that someone at Sony Pictures got the idea to cast them both to relaunch the Men in Black franchise. The film doesn't seem to even try to hide this, what with the Actor Allusion in the scene with Hemsworth throwing a hammer. And also an alien asked Agent M is the Queen which he tried to pledge loyalty eternally which she is not interested, a fate averted by Avengers: Endgame.
- Troubled Production: The film suffered extensive Executive Meddling and a clash of creative visions, as explained here. It's one of the reasons the film has been poorly received.
- When Tom Rothman became head of Sony Pictures' movie division, one of his first priorities to turn the flagging studio around was resurrecting the Men in Black series, which had been in hibernation since the third film. Executives at first conceptualized a crossover film with their 21 Jump Street films, with both franchises' staff collaborating on the project. The problem? 21 Jump Street producer Neal Mortiz didn't agree to it, as he felt it wouldn't count in his contract (he would leave Sony not long after). So the studio opted to create a full-out reboot, one that would not bring either Will Smith and Tommy Lee Jones back as it would prove too costly.
- That's when the clashes began. Director F. Gary Gray and producer Walter Parkes feuded over the script, with Gary preferring a more Darker and Edgier story that would've tackled more contempary issues in society, while Parkes, who had the final say on the film, rewrote the script to make it more lighthearted and less political, something Gray vocally disapproved of. The clashes escalated when an executive vice president, who was seen as a mediator of the conflicts, left the studio during filming. The back and forth of the scripts led to a sense of confusion among the cast, as each day brought a new page of the script. Parkes was also alleged to have usurped Gray as director in some filming days.
- The issues got so bad that Gray almost resigned several times, but was convinced to stay in each of those times by Sony. The studio themselves did little to mitigate the conflict between Gray and Parkes during filming, and was described as being an "absentee landlord" by one insider. Upon completion, the studio tested both Gray's cut and Parkes' cut, with the studio electing to take Parkes' cut as the final product.
- What Could Have Been: Before this film was announced, there were plans for a crossover film between the MIB and 21 Jump Street! During the 2014 Sony email leaks, it was revealed that a sequel to 22 Jump Street was in the works, and would be a Crossover with the MIB franchise as an Affectionate Parody of the shared film universe concept. The film's title was later revealed to be MIB 23, with Tatum and Hill set to reprise their roles. Those plans never seemed to get in gear, and it's since been cancelled.
- Working Title: The film was announced to be simply titled M.I.B. at first, before the change to Men in Black International.
Trivia / Men in Black: International