It's thought the actress landed the lead in the flick, titled Caught in Flight, after Jessica Chastain, star of hit flick The Help, pulled out.
Reports suggest the hotly-anticipated flick will focus on the relationship between Diana and rumoured love interest Hasnat Khan, with director Oliver Hirschbiegel describing the plotline as 'a love story between a princess locked in a tower and an ordinary man.'
Speaking of her latest lead, Naomi gushed: 'It is such an honour to be able to play this iconic role - Princess Diana was loved across the world and I look forward to rising to the challenge of playing her on screen.'
Meanwhile, Hirschbiegel said he was 'delighted to have such a truly exceptional actress who embodies the warmth, humanity and empathy of such a global icon as Princess Diana'.
Do you think Naomi is the right choice? Or would you like to see someone else in the role? Let us know your thoughts in the comments box below…