“We’re thrilled that Stephen Graham has joined the cast of #PeakyBlinders series 6,” the caption said.
Show creator Steven Knight previously said he had devised a role in the drama for Graham but rubbished rumours he would play gangster Al Capone.
Across its six series, the interwar Birmingham-set show has featured guest stars including Sam Claflin as leader of the British Union of Fascists Oswald Mosley and Tom Hardy as Jewish gang leader Alfie Solomons.
In January, it was announced that Peaky Blinders would come to an end after the forthcoming sixth series.
But creator and writer Knight said the story would continue in “another form” and later hinted at a film.
Stephen Graham to make Peaky Blinders debut in new series