David is a tall man of an average build, with notable wrinkles on his forehead and defined nasolabial folds and tear troughs. He has small sky-blue eyes and short, unruly honey brown hair with two prominent tufts curving outwards from the top of his forehead, a short goatee on his chin and wide-rimmed square glasses on his face.
He wears a plain dark blue shirt with a single breast pocket, the two top buttons left casually undone and the sleeve-cuffs unbuttoned and rolled up to just below his elbows. He wears a pair of pale gray-blue jeans, a dark belt with a silver buckle and navy blue sneakers with white soles, decorated with a red stripe near the toe.
When he was younger, he had straighter, shoulder-length hair which he swept backwards, a single thin strand left hanging over his left eye, no goatee, and no notable wrinkles on his face.
He wore a red hoodie, its hood left out over the light gray lab coat he wore underneath, the sleeves of which he rolled slightly up above his wrists. He also wore dark gray pants and black sneakers with white soles and laces.
Like All Might, David is a generally compassionate and altruistic individual, always looking to create new ways to better society as a whole and help those in need. This also applies to his daughter whom he loves dearly and showed himself to be greatly supportive towards her when she learned she was quirkless.
David greatly treasures his friendship with All Might, being positively elated to be reunited with him after several years and holds the Number 1 hero in extremely high regard.
However, David's admiration of All Might almost falls into the realm of blind worship. When he discovered All Might was gradually losing his strength and would eventually have to retire, he refused to accept this and was more then willing to use illegal means to restore his friend's powers, though not to the point where it would endanger people's lives.
David was in a fire accident when he was in his youth. All Might came to his aid, and that was how they met. While All Might was in America, All Might protected the people from villains, while David assisted him.
David Shield seems to be good friends with All Might. He designed All Might's suits, including his original and current suits. He is unaware of the truth of One for All, but is aware that All Might is getting weaker.
Melissa is David Shield's daughter.