- All-Star Cast: The film stars Taron Egerton, Colin Firth, Julianne Moore, Mark Strong, Halle Berry, Channing Tatum, Jeff Bridges, Bruce Greenwood and Elton John.
- Author Existence Failure: Björn Granath, who played the King of Sweden, died during filming.
- Awesome, Dear Boy: Channing Tatum said that he enjoyed seeing The Secret Service and was interested in appearing in the sequel.
- Banned in China: The film is banned in Cambodia due to portraying the country as a haven for bad guys.
- Billing Displacement: Like with the first movie, Taron Egerton doesn't get top billing despite playing the main character. He does move up a few spots, though. Pedro Pascal doesn't get any billing at all, despite clearly having a major role. Elton John however, does get billed above the title, despite his scenes essentially being a gag cameo.
- California Doubling: A significant portion of the film is set in the United States and Southeast Asia, but almost the entire film was shot in the UK.
- The Cast Showoff:
- Creator Backlash:
- Deleted Role: Vinnie Jones' character, a second henchmen to Poppy, was completely cut from the film.
- Deleted Scenes: 80 minutes of deleted footage are known to exist, as confirmed by Vaughn in an interview with Collider.
- Dyeing for Your Art: Jeff Bridges shaved off his beard for the film.
- Executive Meddling: Matthew Vaughn, in his own words, "begged" Fox not to reveal Harry's survival. They didn't listen and made it one of the driving forces of the film's marketing.
- I Knew It!: Many people accurately predicted Roxy's death in the opening attack due to the character having little prominence in the advertising.
- Refitted for Sequel: The scene of Harry teaching Eggsy about proper table etiquette was meant to be in the first movie. It's instead shown here in a flashback.
- What Could Have Been:
- Hoping that Colin Firth would return for the sequel, Matthew Vaughn said that he toyed with the idea of Harry having an Evil Twin before deciding to bring Harry back to life.
- Merlin was supposed to survive. There's even some behind the scene photos on the internet of Mark Strong wearing green leggings to greenscreen in cybernetic legs during Eggsy's wedding. It was changed because test audiences didn't like it, felt it cheapened his Heroic Sacrifice.
- There were originally going to be mentions of the 2016 US presidential elections but were removed due to it being Too Soon. Notably, the movie's fictional President (played by Bruce Greenwood in a bit of a Casting Gag) was to be a direct Expy of real U.S. President Donald Trump, with his Oval Office covered in gaudy red-and-gold leaf a la Trump Tower, but these scenes were later re-shot with a more conventional-looking set and Greenwood putting on a broader Southern Accent, as Vaughn wanted to avoid alienating audiences with an overt political message.
- Tequila was to have a bigger role in the story, but due to scheduling conflicts (because of Channing Tatum working on Logan Lucky), his role was reduced, and some of the scenes went to Whiskey. Notably, Whiskey got the lasso instead of Tequila.
- According to Vaughn, Fox considered splitting the film into two films due to its original run time being three hours and 40 minutes, before he decided to cut 80 minutes into the final cut. He has said that he is planning to release the longer cut in the near future.
- The King of Sweden was going to have a larger role in the third film but Bjorn Granath's death after production concluded for the film prevented this from happening.
- Working Title: Kingsman: The Golden Triangle. It was retitled after test screenings during the early stages of production found it confusing and unaware of its meaning (it's the area that borders Thailand, Laos and Myanmar), though it was eventually referenced as the original name for the Golden Circle in the novelisation.
Trivia / Kingsman: The Golden Circle