Leonardo da Vinci (April 15, 1452 – May 2, 1519) was a Human who lived on Earth during the 15th and 16th centuries. A major figure in Earth's renaissance period, da Vinci was among many other things an inventor, artist, and writer.
The crew of the USS Enterprise met a man named Flint in 2269, an immortal being who had lived on Earth for thousands of years. During Flint's long life, one of his identities was that of Leonardo da Vinci. (TOS episode: "Requiem for Methuselah")
Around 2349, when he was eight years old, Julian Bashir read a biography of Leonardo da Vinci, learning how to create a "memory cathedral" in his mind just as da Vinci had done. (DS9 novel: Cathedral)
In the 24th century, Captain Kathryn Janeway began running a program in which she played the role of apprentice in da Vinci's workshop aboard the USS Voyager. (VOY episodes: "Scorpion Part I", "The Raven", "Scientific Method")
The shuttlecraft Da Vinci on board the USS Defiant was named after the inventor. (DS9 novel: The 34th Rule) The Federation Starfleet also named the USS da Vinci after the man. (Star Trek: Corps of Engineers)
An official Starfleet/Daystrom Institute PADD of Data's internal and external workings (to the android's own flattery) had an introductory diagram of him in the style of da Vinci's Homo universalis ("Universal Man") sketch. (TNG novel: Immortal Coil)