Flagg, James Montgomery (1877-1960),
American illustrator and poster designer. Born in Pelham Manor, New York, he was a regular illustrator by the age of 16 for the periodicals Judge and Life.

He later worked for Cosmopolitan and the Saturday Evening Post. As official New York State military artist in World War I, he designed the famous I Want You poster and others to stimulate recruiting.

Flagg also painted portraits, drew caricatures of celebrities, and wrote books, including the autobiographical Roses and Buckshot (1946).