Gargantua is a book by the French author François Rabelais. Gargantua can also refer to:

Gargantuas, a giant monster from the Japanese film War of the Gargantuas

Gargantua (gorilla) (1929 – 1949), gorilla in the Ringling Brothers Circus

Gargantua (Half-Life), a creature from the computer game Half-Life

Gargantua (comics), a size-changing supervillain from Marvel Comics

Gargantua (solitaire), a solitaire card game

Gargantua River, a river in Ontario, Canada