The Australian-born star racked up an impressive number of credits across his career, and would have turned 39 this April.
He was 28 when he died in New York City on January 22, 2008.
Here we look back on his finest projects.
Patrick Verona in 10 Things I Hate About You (1999)
Teen movies are easy to mock, possibly because it’s a genre so often mishandled. But every now and again a true classic comes along, and 10 Things I Hate About You was just that.
Loosely taking its cues from Shakespeare’s hugely controversial Taming of the Shrew, it provided a breakout success for Ledger – as well as his co-stars Julia Stiles and Joseph Gordon-Levitt.
The movie received generally positive reviews from critics and and grossed just over $50 million at the box office.
Ennis Del Mar – Brokeback Mountain (2005)
That Brokeback Mountain did not win Best Picture remains one of the biggest Oscars shocks of all time – and it was the performances of Ledger and Jake Gyllenhaal that resonated very well with critics and audiences.
Brokeback was a huge success; getting $178.1 million at the box office against a modest budget of just $14 million.
The Joker – The Dark Knight (2008)
The role for which Ledger won his posthumous Oscar, The Dark Knight was in post-production at the time of his death.
His portrayal of the character is often cited as the definitive one: in addition to the Oscar, he also won a BAFTA, Golden Globe, Saturn Award, and a Screen Actors Guild Award.
William Thatcher – A Knight’s Tale (2001)
A medieval adventure comedy, A Knight’s Tale could so easily have been terrible – but actually it was a well-executed, funny affair; anchored by a brilliant lead performance by Ledger.
A Knight’s Tale received some criticism in reviews at the time, but has held up as a great comedy classic for the whole family.
Sonny Grotowski in Monster’s Ball (2001)
This was the movie that won Halle Berry her historic Best Actress Oscar, and Ledger was also phenomenal in a supporting role.
Monster’s Ball still holds up: on Rotten Tomatoes it has a strong 85% rating.