David Tennant, the former 'Doctor Who' star, and Naomi Ackie, the 'Whitney Houston: I Wanna Dance With Somebody' actress, 31, will be joining the movie adaptation of Richard Osman's 2020 crime-comedy novel of the same name.
As well as David and Naomi, Jonathan Pryce ('The Two Popes'), Daniel Mays ('Chicken Run: Dawn of the Nugget') and Henry Lloyd-Hughes ('Killing Eve') will also be appearing in the flick, which follows a group of friends that gather in a retirement home to solve murders for fun, only to find they are caught in a real case.
During an appearance on his podcast 'The Rest Is Entertainment', Richard said: "There's some great names and some more names coming as well.
"I think this is the greatest British cast assembled since the ['Harry Potter'] movies."
The film - which was previously confirmed to star Dame Helen Mirren, Pierce Brosnan, Ben Kingsley and Celia Imrie - is being written and directed by 'Home Alone' filmmaker Chris Columbus, with production due to commence later in June.
'The Thursday Murder Club' started a hugely successful series of books from Richard that have sold more than 10 million copies worldwide - including 'The Man Who Died Twice', 'The Bullet That Missed', 'The Last Devil to Die' and a planned fifth book which is set to be released next year.
The 'Pointless' host previously revealed he had had a desire to write a crime novel for a number of years.
Richard told The Guardian newspaper: "I've always known how hard it is to write a crime novel and I have such respect for people who do it. I never felt I was in a position where I could do it properly and give it the time it deserved until about 18 months ago.
"I decided I would start it and once I got going I found that I couldn't stop. But I decided I wasn't going to tell anybody because I didn't want to be that person who goes around saying, 'Oh yeah, I'm writing a book', but it never happens.
"When I got to the end I thought, well, there at least I've found out that I can do it. But I had no idea what people would make of it."