Enter One World: Together At Home, described as a "global broadcast & digital special to support frontline healthcare workers and the WHO" on its website.
The event -- which will feature dozens of celebrities and musicians -- will be hosted by Jimmy Fallon, Jimmy Kimmel and Stephen Colbert. Lady Gaga also helped to curate it.
The event is meant to encourage people to take action against the spread of coronavirus, through things like staying home and calling on elected officials.
Here's what you need to know about it.