Taking inspiration from Live Aid and Live8, the shows will be the culmination of a year-long campaign that intends to "mobilize everyday citizens, corporations, governments, and philanthropists to end extreme poverty."
The shows will take place in Central Park in New York, Lagos in Nigeria, and yet-to-be-confirmed locations in Europe, Latin America and Asia.
"We're excited to announce that we'll be appearing live at one of these shows," said Metallica in a statement, "along with Billie Eilish, Coldplay, Eddie Vedder, Muse, Ozzy Osbourne, Red Hot Chili Peppers, Pharrell Williams, and many, many more who will fan out around the globe."
"The end of poverty is in sight," say the organisers, "if an additional $350 billion is secured each year for the world’s poorest countries. But to do that, we need governments, corporations, philanthropists, and, most importantly, you, to take action now for people and for the planet. So we can achieve the possible dream."
Global Goal Live will take place on September 26 next year. For more information, visit the Global Goal 2020 website.
Earlier this week, Metallica announced they'd be holding an intimate concert in San Francisco in 2020 to raise money for their All Within My Hands Foundation.
The band also announced that footage from their two recent S&M2 concerts will be screened for one night only around the world on October 9, while pre-screenings will be held on October 5 in London, New York and Los Angeles.
Last week, it was also revealed that Metallica had sold an astonishing 22 million tickets for their concerts since 1982, grossing $1.4 billion in the process, making them arguably the biggest heavy metal band on the planet.