John Q. Public is a reference to the ordinary man or woman. His name is used as a shorthand for popular opinion and a personification of the general public.
Katy Waldman described John Q. Public as follows:
He’s an upstanding sort who shovels the ice off his stretch of sidewalk, writes a check to his local ASPCA, and tries to be a loving dad to his 2½ kids. He sits in traffic. He has a particular order in which he reads the newspaper. Pace Hollywood, he looks nothing like Denzel Washington, though occasionally in the morning, freshly shaven, adjusting his tie in front of the mirror, he thinks to himself that he’s not too bad.
Waldman characterized John Q. Public as a “square who cares,” an upstanding citizen who is reasonably prosperous and is probably a pillar of his community. He can be contrasted with other “everyman” names, like Joe Blow, or Joe Schmo, which usually refer to an ordinary person who’s somewhat down on their luck.
John Q Public was invented in 1922; he was the creation of the cartoonist Vaughan Shoemaker. Shoemaker’s John Q. Public was a symbol for the “beleaguered American taxpayer,” according to the New York Times; he first appeared in the Chicago Daily News. The cartoon was later syndicated to over 75 newspapers around the country.
Shoemaker’s cartoons were likely influenced by an earlier cartoon character, “Mr. Common Man,” which first appeared early in the 20th century and was the creation of the political cartoonist Frederick Opper. Opper invented Mr. Common Man while he was working for William Randolph Hearst’s New York Journal. Opper invented the cartoons during the presidential campaign of 1900, during a time when the Hearst newspapers were going all-out to critique monopolies and “trusts.” Opper, for his part, created an alphabet of characters, each representing a fat trust who blithely kicked and beat a hatless little man who was known as Mr. Common Man.