James and the Giant Peach 's cast consists of Joanna Lumley , Miriam Margolyes , Simon Callow , Richard Dreyfuss , Jane Leeves , and David Thewlis .
Co-stars Joanna Lumley and Miriam Margolyes played James 's aunts in the live-action segments for James and the Giant Peach , and Simon Callow , Richard Dreyfuss , Jane Leeves , David Thewlis , and Margoyles voiced his insect friends in the animation sequences .
James and the Giant Peach -LRB-film-RRB-