Napoléon Bonaparte (born "Napoleone di Buonaparte") was a male Human citizen of France, specifically Corsica, on Earth in the 18th and 19th centuries. He was the leader of the French people. The Napoleonic era was named after him. (TOS: "The Squire of Gothos"; TNG: "Hide and Q")
Marla McGivers adored men like Napoleon and kept a painting, as well as a bust of him in her quarters aboard the USS Enterprise. When Khan visited her quarters in 2267, he recognized Napoleon among her art collection of "bold men from the past."
A 23rd century analogy made by James T. Kirk regarding the creation of the Human Augments, whose superior ability breed superior ambition, was compared to creating a group of Alexanders and Napoléons. (TOS: "Space Seed")
In 2268, Spock listed Napoléon with Ramses, Alexander the Great, Caesar, Hitler, and Lee Kuan as examples of Earthmen whose desire for absolute power corrupted them absolutely. (TOS: "Patterns of Force")
Napoléon's surname Bonaparte was never spoken on screen.
In a deleted scene, eventually cut from the episode TOS: "The Savage Curtain" as aired, Abraham Lincoln made a reference to Napoleon when he mentioned American Civil War-era General George B. McClellan, "The errors, the unforgivable errors I made. McClellan at first appeared to me a veritable Napoleon."