Though it was erroneously reported earlier in the afternoon that Petty had died, his longtime manager confirmed in a statement obtained by ABC News that Petty died at 8:40 p.m. PT Monday evening.
Petty was 66 years old.
Most social media posts, which began pouring in from celebrities this afternoon, have been of sadness and appreciation for the man who helped create many hits during his 40 years in music.
Added actor Kiefer Sutherland: "Today America lost one of its musical giants. Thank you Tom Petty for all the music. To me you will live forever."
Here's what stars had to say about the rock legend on social media.