Héctor Germán Oesterheld, also known as his common abbreviation HGO, was an Argentine journalist, comics editor and writer of graphic novels and comics. He is widely celebrated as a master in his field and as one of the pioneering artists in Argentine modern comics.

A graphic novel is a long-form work of sequential art. The term graphic novel is often applied broadly, including fiction, non-fiction, and anthologized work, though this practice is highly contested by comics scholars and industry professionals. It is, at least in the United States, typically distinct from the term comic book, which is generally used for comics periodicals and trade paperbacks.