Celebrating its tenth anniversary this year, the event sees established performers, writers and directors write and perform six new plays in just one day.
As previously announced, others taking part include: Kaya Scodelario, Anthony Head, Ronni Ancona, Nick Moran, Jeff Fahey, Kaya Scodelario, Zawe Ashton, Neil Stuke, Jaime Winstone, Lesley Manville, Amanda Donohoe, Douglas Booth, Catherine Tate, Tom Ellis, Clive Rowe and Tina Hobley.
Comedian Rob Brydon, who returns to host, described the annual event as "adrenaline fuelled theatre".
"Back in 2007 I ran the gauntlet as a cast member - the fear and the relief once it was over was immense," he said. "I hosted in 2011 - a safe distance from the chaos of being in the cast - and this year I shall return to celebrate the event's ten-year anniversary and fling an astonished eye over the bedlam that will unfold."
The gala raises funds for the Old Vic Theatre Trust and Old Vic New Voices, the Old Vic's dedicated emerging talent, education and community programme. Over the last nine years the 24 Hour Plays event has raised over £1 million.