The drama, which is being penned by Oliver Twist scribe Sarah Phelps, is due to air at Christmas.
The BBC has now announced that Suchet has signed up to play Jaggers, a lawyer who represents Pip's benefactor and Miss Havisham.
The BBC also confirmed earlier reports that Gillian Anderson has joined the cast as Miss Havisham.
Douglas Booth and Ray Winstone have already signed up to star in the drama, while other cast members include Game of Thrones' Mark Addy and Harry Lloyd, Ashes To Ashes actress Claire Rushbrook and Paul Rhys, who previously appeared in Being Human.
Friday Night Dinner's Paul Ritter will also appear in Great Expectations alongside Vanessa Kirby, Jack Roth and Frances Barber.