Imhotep was an Egyptian polymath who was what we would later call a Renaissance man. Of course, Imhotep had a 4000 year head-start on Leonardo. He served the Third Dynasty pharaoh Djoser as vizier, although the complete list of his titles ran:
Chancellor of the King of Egypt, Doctor, First in line after the King of Upper Egypt, Administrator of the Great Palace, Hereditary nobleman, High Priest of Heliopolis, Builder, Chief Carpenter, Chief Sculptor and Maker of Vases in Chief.
His most notable work to modern eyes is the Step Pyramid of Saqqara, in which the pharaoh Djoser was buried. It was the first pyramid, and comparatively small and primitive, but for its time it was an engineering marvel.
After his death, Imhotep was deified, one of very few Egyptians to whom this occurred (other than the pharaohs).