Staff from galleries and venues including the National Theatre will take to the streets, joining children and students for what is being billed as the world's largest climate strike.
Youngsters are taking part in more than 150 demonstrations from Cornwall to Scotland and are urging people to join them to push for action to transform the economy to zero carbon.
Staff from the Tate Modern, Tate Britain and Southbank Centre have also said they will walk out and join the Global Climate Strike in London on Friday.
Oscar-winner Sir Mark Rylance, Shameless star David Threlfall and Year Of The Rabbit's Freddie Fox have called on the National Theatre to back the move.
Their petition has so far been signed by 72 staff.
Sir Mark is a vocal advocate for action against climate change. In June, he quit the Royal Shakespeare Company, objecting to its receipt of funding from oil company BP, which he has accused of obscuring its damaging environmental impact by supporting arts organisations.
Artists and actors will leave their workplaces at 10.30am and converge on Westminster Bridge where they will meet the striking cleaners from the Department of Business before marching on Central London.
Worldwide, campaigners say there are more than 3,400 events planned in 120 countries, with numbers taking part expected to surpass the estimated 1.6 million people who took to the streets for a global climate strike in March.