"[1] In the 2007 documentary Runnin' Down a Dream, Petty said that he felt some initial hesitation about releasing the song, given how straightforwardly it conveys its message.

[2] Jerry Smith, reviewer of British music newspaper Music Week, called "I Won't Back Down" an "extremely catchy, chugging rocker" and expressed the opinion that Jeff Lynne's production "is sure to leave its mark in the build up to the release of his forthcoming LP".

[5] Petty and the Heartbreakers played a quiet but resolute version of the song at the America: A Tribute to Heroes telethon.

[5][6] In January 2015, it was revealed that an agreement had been reached whereby Petty and Jeff Lynne would be credited as co-writers of Sam Smith's song "Stay with Me" and receive 12.5% of its royalties.

[8][9] Smith claimed not to have heard "I Won't Back Down" before writing "Stay with Me",[10] but acknowledged the similarity after listening to the song, calling it "a complete coincidence".

[27] Jim Webb used the song for his successful bid for one of Virginia's U.S. Senate seats in 2006, as did Hillary Clinton during the 2008 Democratic presidential primary campaign.