Being born and raised in Edinburgh, Charleson attended the Royal High School and then went on to attend Edinburgh University. He initially studied architecture but switched to an MA degree after cultivating an interest in acting. He won a place at the London Academy of Music and Dramatic Art after graduating from Edinburgh.
In preparing for his role of Eric Liddell in Chariots of Fire, Charleson read the Bible from beginning to end. His name was used posthumously for the Ian Charleson Awards, which have been presented annually since 1991 to reward the best classical stage performances by actors aged under 30. Sir Ian McKellen said that Charleson played Hamlet so well it was as if he had rehearsed the role all his life. He died while playing Hamlet in Richard Eyre's production at the Olivier. Studied architecture at Edinburgh University, but apparently this area was his weakest point: He once designed a model of a magnificent bridge without foundations.