Ewan McGregor
Mark Renton was an early career role for Scottish actor Ewan McGregor, and one that helped launch him to stardom. He starred in a few TV movies and series in the mid 1990s, before earning a lead role in Danny Boyle’s breakout film, Shallow Grave (1994), for which he won an Empire Award for Best British Actor. McGregor’s performance in Shallow Grave impressed Boyle and producer Andrew Macdonald, leading to their casting him as Renton. To play Renton, McGregor lost 28 pounds and shaved his head to magnify his gaunt appearance. To learn more about heroin, he read several books on addiction and met recovering heroin and crack addicts at the Calton Athletic Recovery Group in Glasgow. He also learned how to cook up heroin with a spoon and considered injecting it to better understand the character but ultimately decided against it. For his role as Renton, McGregor earned the Empire award for Best British Actor.
Jonny Lee Miller
Johnny Lee Miller was a Londoner who got his start as a child actor in television. His first film was Hackers (1995). His American accent in that film caught director Danny Boyle's attention, and he was asked to audition for Trainspotting. At his audition, he read the role of Sick Boy in a Sean Connery accent (Sick Boy is obsessed with Sean Connery throughout the film), which impressed Boyle enough to cast him as the only non-Scottish member of the lead ensemble.
Ewen Bremner
Ewen Bremner is a Scottish actor who had already played the role of Renton in the stage adaptation of Trainspotting. He agreed to take on the role of Spud in the film, stating that all of the characters felt like "part of [his] heritage.” He had already appeared in a couple of films before Trainspotting, but his role as Spud played a major part in launching an international career.
Robert Carlyle
Robert Carlyle is a Scottish actor who was already a famous TV actor in Britain before landing the role of Begbie, which has remained one of his highest-profile career roles. Begbie is a pivotal role in the film and one that Carlyle plays with menacing aggression and psychopathy. Carlyle said of his role, "I've met loads of Begbies in my time. Wander around Glasgow on Saturday night and you've a good chance of running into Begbie." The role of Begbie helped to launch Carlyle’s career, as he went on to play villains and psychopaths in several other productions.
Kevin McKidd
Tommy was the second film role for Scottish actor Kevin McKidd, after his screen debut in Small Faces earlier in the same year. McKidd was just starting out as a stage actor, studying drama at Queen Margaret College in Edinburgh, when he was cast in the role. McKidd needed to lose weight and muscle mass over the course of filming, to show Tommy’s descent into addiction and illness.
Kelly Macdonald
Danny Boyle wanted to cast an unknown actress for the role of Diane so that the audience would believe a 19 year old playing the part of a 15 year old. Boyle and his team hung flyers for a casting call in pubs around Edinburgh to advertise the part, and Macdonald found one while working at a bar. She played the part as an arrogant, manipulative, and unruly teen, and her school uniform and short haircut helped to convince the audience she was younger than she was. However, her dress and make-up at the club when we first meet her matured her appearance, making Renton’s mistaking her for an adult believable.
