- Breakthrough Hit: This was the first film to feature a musical score by Erich Wolfgang Korngold, one of Hollywood's greatest composers. Korngold was given three weeks to score the film, although during the day he was working on adapting the score of an operetta for Paramount called Give Us This Night (1936). He worked nights on the score for this film.
- California Doubling: Nearly all of the movie was filmed on a soundstage in Hollywood in the summer of 1935, apart from a few scenes shot at Laguna Beach, California (standing in for a Caribbean shore).
- Completely Different Title: In Germany, the film was released as Under the Pirate Flag.
- Creator Backlash: Basil Rathbone felt miscast as a French pirate.
- Darkhorse Casting: Prior to this, Errol Flynn only had a couple of bit parts in films.
- Dueling Works: With Mutiny on the Bounty, another naval epic.
- Fake Irish: Australian Errol Flynn as Peter Blood.
- Fake Nationality: South African-born Englishman Basil Rathbone plays the French pirate Levasseur.
- Follow the Leader: Warner Bros. were inspired to remake the film, which they had first made as a silent in 1923, after the popularity of Treasure Island (1934) and The Count of Monte Cristo revived the Swashbuckler genre in Hollywood.
- Name's the Same: The English title for the French swashbuckler Le Capitan happens to be Captain Blood as well, even though it's not the same story or characters at all.
- Romance on the Set: Errol Flynn allegedly had an affair with Ross Alexander during filming.
- Star-Making Role: For Errol Flynn and Olivia de Havilland.
- Those Two Actors: This was the first of nine movies made together by Warner Brothers' romantic couple Olivia de Havilland and Errol Flynn.
- What Could Have Been:
- Robert Donat was originally set to star, but he dropped out due his asthma. James Cagney, Ronald Colman, Clark Gable, Leslie Howard and Fredric March were all considered before Errol Flynn was cast. Warner Bros. considered loaning out Cary Grant from Paramount to star in the film, but Michael Curtiz thought he was "too effete".
- Bette Davis tested for Arabella.
Trivia / Captain Blood