Hoagy Carmichael - In the very first Bond novel, Casino Royale, author Ian Fleming describes Bond as resembling this American composer, singer, pianist and actor. Bond's love interest Vesper Lynd remarks "Bond reminds me rather of Hoagy Carmichael, but there is something cold and ruthless." In his third Bond novel, Moonraker, Fleming again has a character note the resemblance describing Bond in this way: "Rather like Hoagy Carmichael in a way. That black hair falling down over the right eyebrow. Much the same bones. But there was something a bit cruel in the mouth, and the eyes were cold" Hoagy Carmichael Fun Fact: His most famous songs, Stardust and Heart and Soul are two of the most recorded American songs in history (who keeps track of this stuff?).
Barry Nelson - He is the first actor (and so far the only American) to portray Fleming's secret agent. He appeared as American agent Jimmy Bond in a 1954 adaptation of Casino Royale for the Television anthology series Climax! I own this but can't bring myself to watch it.
Cary Grant - the suave, debonair star was Fleming's top choice. He doesn't really resemble the author's description of the character though. Anyway - Grant was too big a star and too expensive.
David Niven - the equally suave British actor turned down the role because he felt he was too old (he was 51 when Dr. No began filming). He ended up playing the character in the 1967 comedy adaptation of Casino Royale.
Patrick McGoohan - this American-born actor (who spent most of his life in the UK) was currently starring in the British TV series Danger Man (known as Secret Agent here in the US) and turned down the offer to play 007. A few years later he co-created and starred in the cult classic spy-drama The Prisoner.
Musical Interlude: Speaking of Secret Agent, when it was shown in the USA, a nifty new theme song by singer-songwriter Johnny Rivers was added. Here's Rivers lip-syncing the song on some mid-60's American Bandstand clone.
Richard Burton - the British actor had just won a Tony Award for Best Actor for his portrayal of King Arthur in the musical Camelot. In 1965 he was nominated for an Oscar for his role in the film version of John Le Carre's Cold War drama The Spy Who Came in from the Cold. I wonder if Liz Taylor would have replaced Ursula Andress as Honey Ryder?
Stewart Granger - the British actor was a popular leading man at the time and had even played H. Rider Haggard's famous hero Allan Quatermain in King Solomon's Mines. He might have made a decent Bond.
There you have it the actors who might have been Bond. Sean Connery was chosen and the rest is history.