Hugh Grant filmed his scenes with Charlie Hunnam in five days; he had to deliver over 40 pages of dialogue during the shoot.
Hugh Grant revealed on The Graham Norton Show (2007) that he had not met Matthew McConaughey during the shoot of The Gentlemen (2019). In fact, the first time they met was on that same Graham Norton show.
To help with his long, monologue-heavy shoots, Hugh Grant wrote a cheat sheet. The night before he was scheduled to shoot, his car was broken into. The robber took his script and the cheat sheet, so Grant needed to go without them.
There were no table readings for this film. Instead, Guy Ritchie had the cast do full dress rehearsals with a multi-angle camera crew. Ritchie would then review footage of the scenes and revise the script accordingly.