Half-giants are a mythological creature, born to a giant and a human, or some other creature. They feature primarily in fantasy role-playing games, where they often are a playable race (for example, as in the Dark Sun setting for Dungeons & Dragons), and in literature such as the Harry Potter books. Examples in the Harry Potter series include Rubeus Hagrid and Olympe Maxime.

Some scholars suggest there are biblical precedents for the existence of giants. Before God flooded the earth, he was angry at the sinfulness of his creation. One story in Genesis includes his anger at "the sons of God" having children with "the daughters of men." These half breeds were known as "Nephilim," and they were a race of giants. Read a version of Genesis 6 (including the reference above) here. More discussion of Nephilim as giants can be found in the Dead Sea Scrolls.