More than £1 million was raised at a glamorous gala night at the Old Vic to help transform the historic theatre.
The money will go towards building a £17 million five-storey annexe to help promote emerging talent and work with its neighbours in south London.
Actresses Sheila Atim and Ellie Bamber were among the guests at the event which featured performances from Groundhog Day and Matilda the Musical as well as a quiz hosted by Sir Ian McKellen.
Artistic Director Matthew Warchus said: “I think it occurred to me when I arrived at the Old Vic that amongst the many things it has to offer it doesn’t really have a suitable space for emerging talent.
“It’s a 1,000-seat theatre and it’s a very big spotlight on somebody who might just be at the early stages of their career and a studio space, which will be part of this package, is a sort of missing link.”
He said the studio, which will host more experimental pieces and short runs of work still being developed, would allow paying audiences to see the next generation of performers.
He said: “Its main purpose is for people who are making their way towards a larger stage.”
Mr Warchus, who has headed the historic Waterloo theatre since 2015, said the plans which also include a writer’s room, a script library and space for local schoolchildren to do their homework, were inspired by the theatre’s “strong sense of social mission,” and would help “demystify” the venue by building on its outreach work in the capital.
He said: “It’s great we can do it but when you do it off site you don’t have the chance to demystify the process of coming to the theatre.
“I really want to make it a welcoming thing and by bringing these projects right next to the theatre you develop a connection between people who aren’t traditional theatregoers so they are there and they get to see what the venue is like and hopefully it breaks the ice for them.”
