Gregory Peck as Capt. Horatio Hornblower R.N

Virginia Mayo as Lady Barbara Wellesley

Robert Beatty as Lt. William Bush

Moultrie Kelsall as Lt. Crystal

Terence Morgan as 2nd Lt. Gerard

James Kenney as Midshipman Longley

James Robertson Justice as Seaman Quist

Denis O'Dea as RAdm. Sir Rodney Leighton

Richard Hearne as Polwheal (Hornblower's Batman)

Michael Dolan as Surgeon Gundarson

Stanley Baker as Mr. Harrison (Bosun)

Alan Tilvern as Hernandez

Alec Mango as El Supremo (Don Julian Alvarado)

Christopher Lee as Spanish Captain

John Witty as Capt. Entenza

Michael Goodliffe as Col. Caillard - POW Escort

Eugene Deckers as French Commandant

Ingeborg von Kusserow as Hebe (Lady Barbara's Maid)

Amy Veness as Mrs. McPhee (Hornblower's Housekeeper)

Kynaston Reeves as Adm. Lord Hood

Ronald Adam as Adm. McCartney

Chris Adcock as Crewman (uncredited)

Basil Bartlett as Capt. Elliott (uncredited)

André Belhomme as French Guard (uncredited)

David Birks as Crewman (uncredited)

Robert Cawdron as "Witch of Endor" French Mate (uncredited)

Diane Cilento as Maria Hornblower (voice) (uncredited)

Howard Connell as "Lydia" Seaman (uncredited)

Alexander Davion as Spanish Officer (uncredited)

Steve Donahue as Crewman (uncredited)

Patric Doonan as Seaman (uncredited)

Anthony Forwood as Lt. Woodford (uncredited)

Arthur Gomez as French Corvette Captain (uncredited)

Lindsay Hooper as Crewman (uncredited)

Richard Johnson as Macrae (uncredited)

Howard Lang as Officer Aboard Cassandra (uncredited)

Jim Brady as Bosun's Mate (uncredited)

Fred Haggerty as Seaman (uncredited)

Sam Kydd as Seaman Garvin (uncredited)

Anthony Marlowe as Capt. Bolton (uncredited)

Michael Mellinger as Spanish Officer (uncredited)

Julio Monterde as Spanish Officer (uncredited)

Peter Morton as Hommel (uncredited)

Jack Stewart as Seaman (uncredited)

Derek Sydney as Capt. Elliott (uncredited)

Jack Taylor as Seaman (uncredited)

John A. Tinn as Juan (uncredited)

Russell Waters as Seaman (uncredited)

Del Watson as Crewman (uncredited)

Jack Watson as Capt. Sylvester (uncredited)

Byron Webster as Seaman (uncredited)

Patrick Young as Lt. Radot (uncredited)