Fleming actually wanted Niven as Bond, but the only time he played him was in a spoof, that was not part of the actual series of canonical films.

Also since Barry Nelson played "Jimmy" Bond a CIA agent the first actor to technically play the Actual James Bond of British intelligence was Bob Holness in 1955

@LenHazell53 hollywood did not thought the sophistication of the audience will understand MI6. Also I read hollywood got the CIA wrong, it was not CIA, it was something else made up. Hollywood did knew CIA operates outside of USA and the play was in the states. You can bend it like beckum all you want and still will be the first impersonation of Flemming's Bond, James Bond. David Niven played Bond in the 2nd incarnstion of Casino Royale, it was the only book they didn't have the rights so was done as they pleased.