Matthew Vaughn cast Henry Cavill because "he needed someone who was born to play James Bond--which Henry is--and then nick him before Bond's studio did." Cavill was, in fact, a finalist to play Bond in Casino Royale (2006), but was rejected for being too young (he was then 22).
In October 2023, Matthew Vaughn announced his plans to create a larger spy-themed universe through his Marv Studios, with that universe being interconnected and comprising the Kingsman films, the Argylle films, and an unnamed third series. His intention was to have the new upcoming films in each series culminate in a crossover in the future.
Argylle is named after the limo driver from the first "Die Hard" movie.
Matthew Vaughn secured the rights to The Beatles: Now and Then (2023) a year before it was released. The song was being developed by Giles Martin, the son of longtime Beatles producer Sir George Martin, and Giles also served as music producer on Argylle. Vaughn recalled, "I was with [Giles] and I said, 'I'm really struggling to find what I call the romantic song of the movie, 'cause I need it to be sad, but hopeful...' And he said, 'Do you want to hear a new Beatles song?' And Giles has got a hell of a sense of humor, so I was like, 'Yeah, yeah. Whatever.' And he goes, 'No, I'm being deadly serious.' He played it to me, and it was as if Lennon had seen the film... We just slapped it on the movie, and we didn't have to edit anything - it just fitted the picture."
Jason Fuchs: The film's writer makes a brief appearance as the moderator for Elly Conway's book readings.