Leonardo is about average height and build for the 1920s, standing several inches short of 6 feet.  His hair has silvered over the years, though the once dark hair has not thinned significantly. When out of doors, Leo covers his head with a bowler hat. His clear, blue eyes have crow's feet near the corners, though his age is not apparent on his face in many other ways. Leo has always been quick to flash a winning smile, though it's been a little more infrequent of late. He usually follows up a joke with a smirk, and laughs easily when others display a sense of humor.

Leo always dresses well, wearing a wide variety of Italian-made suits. He prefers non-gray colors in his suits and shirts so as not to draw attention to the graying of his hair. His shoes are always polished and are generally imported as well. His hands appear well cared-for, and are as steady as a surgeon half his age. He generally avoids facial hair, though when it does grow there is some evidence of both black and gray peeking through his cheeks.