The trio, alongside Sherlock Holmes actor Eddie Marsan and Stephen Graham, would join Ian McShane in Rupert Sanders's fairy tale adaptation.
Former Lovejoy actor McShane was cast as the dwarf leader earlier this week.
In a departure from the well-known Disney telling of Snow White, Huntsman's dwarfs will be warriors called Caesar (McShane), Tiberious (Izzard), Constantine (Hoskins) and Claudius (Jones), says The Hollywood Reporter.
The movie will see Twilight actress Stewart take on the role of Snow White as she tries to escape the clutches of her evil stepmother (Charlize Theron) with the help of a huntsman (Chris Hemsworth) originally sent to kill her. Pirates of the Caribbean: On Stranger Tides star Sam Claflin will play Prince Charmont.
Snow White and the Huntsman is due to open in cinemas in June 2012, three months after the scheduled March debut of the Julia Roberts-led rival project The Brothers Grimm: Snow White.