The unscripted episode will air on the HBO Max streaming service, launching in May. A date is yet to be announced.
Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc, Matthew Perry and David Schwimmer will all appear.
Perry posted on Instagram: “It’s happening” with a photo of the cast from the 1990s. The rest of the cast then started sharing the same post.
Friends aired from 1994 until 2004. The final show was watched by 52.5 million viewers in the US, making it the most watched TV episode of the 2000s.
The show has since picked up legions of younger fans through Netflix.’
It was the UK’s favourite streaming show and Netflix’s second most popular show in the US in 2018.
Rumours of a reunion intensified after Aniston posted a photo of the cast together on Instagram in October.