Richard Todd

as Wing Commander Guy Gibson, V.C., D.S.O., D.F.C.

Michael Redgrave

as Doctor B. N. Wallis, C.B.E., F.R.S.

Ursula Jeans

as Mrs. Wallis

Basil Sydney

as Air Chief Marshal Sir Arthur Harris G.C.B., O.B.E., A.F.C.

Patrick Barr

as Captain Joseph (Mutt) Summers, C.B.E.

Ernest Clark

as Air Vice-Marshal The Hon. Ralph Cochrane G.B.E., K.C.B., A.F.C.

Derek Farr

as Group Captain J. N. H. Whitworth, D.S.O., D.F.C.

Charles Carson

as Doctor