Gladiator is a science fiction novel by American author Philip Wylie, first published in 1930. The story concerns a scientist who invents an "alkaline free-radical" serum to "improve" humankind by granting the proportionate strength of an ant and the leaping ability of the grasshopper. The scientist injects his pregnant wife with the serum and his son Hugo Danner is born with superhuman strength, speed, and bulletproof skin. Hugo spends much of the novel hiding his powers, rarely getting a chance to openly use them.

Philip Gordon Wylie was an American writer of works ranging from pulp science fiction, mysteries, social diatribes and satire to ecology and the threat of nuclear holocaust.