The man behind it was Irish musician Bob Geldof, who'd been moved by pictures of Ethiopian famine victims.
Today, 20 years on, Geldof has announced a new series of concerts.
They'll take place on 2 July in London, Philadelphia, Rome, Paris, and Berlin and feature acts such as U2, R.E.M., and Sting.
Geldof says the event is a unique opportunity to do something unparalleled: "And that is to tilt the world a little bit on its axis in favor of the poor, and it's not a difficult thing to do."
The first Live Aid raised millions of dollars for the starving in Africa.
This time, the concerts are free, and there's a different aim -- to put pressure on world leaders to tackle poverty.
The concerts will take place just days before leaders of the world's rich countries meet in Scotland for the G-8 summit on 6-8 July.
Anti-poverty campaigners hope the G-8 leaders will be listening to the message of "Live 8."
Stephen Rand works with the "Make Poverty History" campaign, which is calling for debt relief and an international trade system that is fairer to poor nations.
"'Live 8' is going to take the message right around the world and give attention to it in a way that'll make it really hard for the leaders to ignore," Rand says.
1985's Live Aid wasn't the first time Western popular musicians had gotten together and played for charity.
But the event was on a grander scale than anything before -- and it set the standard for the many musical charity events that followed, according to British popular music critic Simon Warner.
"There was a history of popular music and politics coming together before that, [like] the civil rights movement in America, the anti-Vietnam movement. But I think Live Aid was special because it didn't have so much of a political face, it was more of a humanitarian affair," Warner says. "Here were artists burying their particular political feelings and supporting a cause for humanity, the battle against starvation and hunger in Africa. It also influenced other projects, other productions, the support that musicians like Bono and Bruce Springsteen gave to Amnesty International, the sorts of efforts that were made on behalf of Nelson Mandela in South Africa. Live Aid was influential on productions that happened after that."
Organizers are hoping that "Live 8," like its predecessor, will have a lasting impact.