Kenneth Williams as Captain Fearless

Bernard Cribbins as Midshipman Albert Poop-Decker

Juliet Mills as Sally

Charles Hawtrey as Walter Sweetly

Donald Houston as First Officer Jonathan Howett

Percy Herbert as Mr. Angel, the Bos'un

Jim Dale as Young Carrier

Patrick Cargill as Don Luis, the Spanish Governor

Cecil Parker as First Sealord

Ed Devereaux as Hook, Pirate

Peter Gilmore as Patch, Pirate Captain, aka Roger

George Woodbridge as Ned

Ian Wilson as Ancient Carrier

Jimmy Thompson as Adm. Horatio Nelson

Anton Rodgers as Hardy

Marianne Stone as Peg

Viviane Ventura as Spanish Secretary

Frank Harper as Man at Dirty Dick's (uncredited)

Jack Carter as Marine (uncredited)