But in his new film, "A Knight's Tale," Ledger is the star. His name comes first in the credits, and his face is on the poster that adorns magazines and billboards nationwide. And after the film's May 11 release, fans are likely to come running.
The 22-year-old Ledger isn't letting the prospect of idolhood get to him yet.
"I really don't sit around worrying about that," he said. "I don't think it's worth the time and effort getting concerned about that. If it happens, it happens, and it's not in my control."
"A Knight's Tale" tells the story of a poor peasant squire (Ledger) who rises above his status to impersonate a knight in 15th-century England's jousting circuit. The film, shot in Prague with an ensemble cast, required Ledger to dance, ride horses and wear armor.
Although the success of "A Knight's Tale" is riding on Ledger, he's not at all nervous.
"Ultimately, it's $50 million, but it's not my money," he said. "So shit, I don't have the pressure of losing it."
And the amount of money invested in a film, Ledger said, doesn't affect the way he does his job. "Basically I'm turning up and I'm acting, and my job doesn't differ from a $3.5 million movie," he said. "Between action and cut, you know, no amount of money can change what I do."
The film's ensemble cast also helped take the pressure off. "I never felt like the movie was riding on my shoulders," Ledger said. "I certainly never felt my head should be on the poster like that."
Despite his newly poster-worthy face, Ledger still has a laid-back approach to his career. "It's just about me taking each day and dealing with it as it happens -- and not feeling I have to plan the rest of my life."