Despite heavy criticism, the 2003 superhero film Daredevil is very much a pioneer, bringing many "firsts" to Hollywood. For instance, it cast Ben Affleck in his first superhero role. Oddly, it also marks a "first" for actor Colin Farrell, as Daredevil is the first American film to feature his natural Irish accent.
Farrell made his feature film debut in 1997 when he appeared in the film Drinking Crude, but started acting in American productions by the year 2000. Appearing in films such as Tigerland, The Recruit, Phone Booth and Minority Report, he took on an American accent, all the way up until Daredevil.
Daredevil tells the story of Matt Murdock (Ben Affleck), a lawyer who moonlights as the titular vigilante. Having lost his eyesight in an accident, Matt's other senses have become exceptionally heightened, allowing him to see through the vibrations of movement. One of the film's two primary villains is Bullseye (Colin Farrell), an assassin who shoots and throws with perfect accuracy. However, when Daredevil gets in the way and causes him to miss a target, he has an identity crisis and makes it his personal mission to take d0wn the Devil of Hell's Kitchen.
At the time of Daredevil's production, Bullseye's origin and real identity was unspecified. In the comics, he'd used the alias Benjamin Poindexter on several occasions, but some knew him as Lester. No ethnic background or place of origin was specified.
Given the the character's ambiguous background and unspecified real persona, director Mark Steven Johnson had some creative liberty with the character. Because Johnson already had an Irish actor, he thought it'd be cool to make Bullseye Irish. This allowed Colin Farrell to use his natural accent for the very first time since his transition to American films. However, a year after Daredevil was released, it was revealed that Bullseye's real name was Leonard and that he was from Queens, New York, in the miniseries Bullseye: Greatest Hits.
In an interview with CBR from 2003, Farrell talked about the changing of Bullseye's origin and speaking in his natural accent. "It was nice. That was Mark Steven Johnson's idea. He said to me, because it was never specified in the comic book where Poindexter/Bullseye was from, so he said, 'You can do it in the Irish accent,' and I was like, 'Fuck yeah, man. Definitely.' I mean I even did a stronger Dublin accent than what I have. (with heavy accent) 'Did all the Bullseye and all that shite, you know.' It was fun to play. And I had no dialect coach whispering in my ear between takes, that bastard! Sick of 'em!"
After the release of Daredevil and consequential reveal of Farrell's accent, the actor was given more freedom in using it. From then on, he played more Irish characters and even used his natural speaking voice without any further explanation from the given story. Films such as Seven Psychopaths, The Beguiled and The Killing of a Sacred Deer are a few where his accent was used.