Alan Ford said he is “delighted” to be joining EastEnders as a character “close to my own age”.
The Riot Club star, 85, will play Stevie, the estranged father of Billy Mitchell (Perry Fenwick) who grew up in care from the age of 10 after Stevie took sole custody of his brother Charlie.
The pair last saw each other 25 years ago.
“I feel highly delighted to be playing a character close to my own age in this extremely popular television drama series,” Ford said.
Stevie will arrive in Walford as the Mitchell family prepare to say goodbye to their beloved Aunt Sal, “but it soon becomes apparent that his attendance is not welcome”, the BBC said.
The funeral of Aunt Sal on-screen comes after the death of actress Anna Karen last February in a house fire at the age of 85.
Ford has had an illustrious career spanning more than five decades, and is best known for starring in Guy Ritchie films including Snatch in 2000 alongside Brad Pitt, Jason Statham and Vinnie Jones, as well as Lock, Stock And Two Smoking Barrels two years earlier.
Chris Clenshaw, EastEnders executive producer, said: “It’s an honour to welcome the immensely talented Alan Ford to the cast of EastEnders as he takes on the role of Stevie Mitchell.
“Whilst Billy has been a stalwart in the show for over 25 years, viewers know very little about his complicated childhood and the events that led him to grow up in care.
“Alan arrives in Walford as the Mitchell family prepare to say goodbye to their beloved Aunt Sal but it soon becomes apparent that he is not welcome in the family fold.”
The BBC said Ford has begun filming and his first scenes will appear on screen in the New Year.