- Ability over Appearance: Christy was written to be 12 or 13 years old but Jim Sheridan ended up casting 10 year old Sarah Bolger in the role after she impressed him. Which gives us a weird line where Christy's narration says "and that's when the baby was conceived". Sure a 13 year old knowing about conception is understandable but a 10 year old, not so much.
- Actor Allusion: The London accent that Johnny is asked to do at an audition is actor Paddy Considine's real accent.
- California Doubling: The street fair scene was filmed in Dublin.
- Fake American: A few American bit parts are played by Irish actors.
- Fake Irish: Paddy Considine and Samantha Morton are both British, but do pretty good Irish accents.
- The Pete Best: Sarah Bolger actually never intended to audition for the film. Her sister Emma auditioned for Ariel and then said to Jim Sheridan to meet her sister who was in the car outside.
- Playing Gertrude: A fourteen year age difference between Samantha Morton and her on-screen eldest daughter Sarah Bolger. Likewise an eighteen year difference between Paddy Considine and Bolger. What's more is that Christy was written to be two or three years older, making this more pronounced.
- Real-Life Relative: As stated many times, the Sullivan sisters are played by real-life sisters.
- Reality Subtext: The dead son Frankie is named after the director's late brother, and the film is dedicated to him.
- Separated-at-Birth Casting: The resemblance between Sarah Bolger and Samantha Morton definitely makes them believable as mother and daughter. Now that Bolger has grown up, she resembles Morton even more.
- What Could Have Been:
- The story would originally have taken place in 1982, which is why the characters go to see E.T. the Extra-Terrestrial - Jim Sheridan having based it off his own experiences in America. However the tight budget meant it had to be set in the present day. The filmmakers lucked out when ET was re-released in 2002, to celebrate its twentieth anniversary.
- Katey Harvey auditioned for the role of Christy.
- The movie was originally supposed to star Ewan McGregor as Johnny and Kate Winslet as Sarah when the movie was titled East of Harlem.
- Working Title: East of Harlem
Trivia / In America