It’s impossible to know. Humans have been making ceremonial breads in all manner of shapes (especially and including the human form) since time immemorial. And even though gingerbread is a fairly recent innovation, there’s really no way to tell who might have fashioned that particular bread into a person-shape first.
Even so, more than a few people credit the popularization of the gingerbread man to Queen Elizabeth the First, who reigned over England during the English Renaissance. So the story goes, Elizabeth had a habit of presenting important visitors with gingerbread likenesses of themselves which she herself made. I don’t know if the story is true or not, however she’s also known as “The Virgin Queen”, so she obviously had a lot of extra time on her hands.
Who might those important visitors have been? A short Who’s Who would have included Shakespeare, Christpoher Marlowe, Edmund Spenser, Ben Johnson, Sir Walter Raleigh, Sir Francis Drake and Francis Bacon, to mention just a few. All I can say is she must have been wicked good with a pastry bag, because those frilly Elizabethan collars couldn’t have been easy to render in icing.