Great Ape (大猿, Ōzaru, lit. "Great Monkey") or Oozaru is a giant, monkey-like creature that Saiyans can transform into to increase their enormous strength. Originally in the series, the Great Ape was a transformation for Goku, being a parody of a monkey king character named Sun Wukong from the novel The Journey to the West. Later in the series, the Great Ape is discovered to be a transformation that is only accessible to characters who possess heritage from the Saiyans.

The original Japanese name literally translates to "great ape", "giant ape", "king ape", or "large monkey", though Toriyama appears to be the first to have applied it to primates of very gigantic proportions. Goku, Gohan, and other Great Ape forms in a flashback voice effects were done by Shane Ray.