1 Harrison Ford-He was 31 when he first had a somewhat prominent role. 2  The film was American Graffiti. 3  He true breakout wasn't until Star Wars, when he was 35.4  As most know, just before being cast as Han Solo, he was moving back to his carpenter roots. The role of Han Solo eventually went to him. 2  Viggo Mortensen-He had some bit roles in his late 20s (ironically had a bit part in Harrison Ford's Witness in 1985, when he was 27). 3  His more prominent supporting role came in 1990 in Young Guns II, when he was already 33.