The Brit, who shot to fame as a schoolboy ballet dancer in Billy Elliot, fell in love with the 1996 hit after watching it behind his parents' back when he was a young boy.
It is based on author Welsh's dark story of a group of heroin addicts in Edinburgh, Scotland and Bell was determined to one day star in another Welsh film - so he was delighted with the opportunity to play a cop in upcoming movie Filth.
He tells InStyle magazine, "I just had to have an Irvine Welsh film on my resume. I was a huge fan of Trainspotting as a kid - I saw it long before I should have! That world of odd characters was so full of life and so vibrant."