Although the character was inspired by many real-life spies, the author Ian Fleming took the name James Bond from an ornithologist.
In 1952, Ian Fleming living in an estate in Jamaica and writing his first James Bond book, Casino Royale. (The estate, by the way, was called Goldeneye – named after either a 1941 book or a WWII spy plan that Fleming had worked on.) His protagonist was a spy inspired by many real spies that Fleming knew during the war, and also a fictional spy from the writings of Denis Wheatley. But he didn’t have a name for this new character.
Fleming needed the name to be extremely nondescript. In his own words,
I wanted the simplest, dullest, plainest-sounding name I could find. […] Exotic things would happen to and around him, but he would be a neutral figure.
Fleming was a bit of a bird-watcher, and he happened to have a book on his shelf called Birds of the West Indies. The author: the ornithologist James Bond.
You can see a picture of the real James Bond above – and he is a very unlikely inspiration for this literary figure. Bond (the real one) was amused by this homage, and twelve years later actually surprised Fleming with a visit. He got a signed first-edition out of it, and endless bragging rights I imagine.