Sir Elton John, Jennifer Lopez and Stevie Wonder will perform in a live TV special, under the direction of Lady Gaga, to show support for healthcare workers fighting the coronavirus.
The One World: Together At Home event will be broadcast tonight on several US networks and streamed on social media.
More than 100 stars will perform from their homes across the world, to create the two-hour concert.
Gaga and advocacy organisation Global Citizen have already raised $35m (£28m) in seven days for the World Health Organisation's (WHO) COVID-19 Solidarity Response Fund, according to the singer.
Fans will be able to watch the show live on Instagram,YouTube, Apple, Facebook and Twitter at 1am UK time.
The full show will also be replayed at 7.15pm on Sunday on BBC 1.
During a news conference, Gaga said: "We want to highlight the gravity of this historical, unprecedented cultural movement, and we want to celebrate and encourage the power of the human spirit."