- Godzilla, Found on an island asleep, but when it started to rain one day, the humans planted a sword on top of the cave Godzilla is asleep in, the sword was used as a lightning rod, and the lightning hit the sword, awakening Godzilla, and causing him to destroy the Red Bamboo's labs and bases, and fighting Ebirah, and the Giant Condor
- Ebirah, the main antagonist of the film, a giant shrimp who is controlled by the criminal organization known as the Red Bamboo
- Mothra, Appears on the island to rescue the humans from the island, Mothra's twin fairies tell the humans to build a giant basket, so that the humans may stay in there while Mothra carries it and flies away.
- Giant Condor, a giant bird who briefly appears to fight Godzilla, but is killed by his atomic breath
After a man called Yata is lost at sea, his brother Ryota steals a yacht with two friends and a bank robber to find him. The crew runs afoul of the giant shrimp called Ebirah, and is washed ashore on an island, where a criminal organization called The Red Bamboo manufactures a yellow liquid to keep Ebirah under control. They keep natives from Infant Island and treat them as slaves to create the liquid, and the natives wish for Infant Island's god, Mothra, to rescue them.
While avoiding capture, Ryota and his allies, aided by a native who escaped captivity, stumble across Godzilla who is sleeping in a cavern. The group makes a plan to defeat the Red Bamboo and escape the island. Later, they wake up Godzilla using a lightning rod, who rampages through the labs and bases of the Red Bamboo. Godzilla even fights Ebirah briefly, but it retreats. Later, Godzilla is attacked by a Giant Condor, who is also controlled by the Red Bamboo, but is killed when Godzilla fires its atomic breath at it. The humans are told to build a giant basket for Mothra.
The humans free the enslaved natives, while Godzilla destroys the base. Godzilla also smashes a tower, and accidentally triggers the island to self-destruct. Godzilla then fights Ebirah once again, but Godzilla rips Ebirah's claws off, and Ebirah retreats into the ocean. The natives summon Mothra to save the humans, who has a very brief encounter with Godzilla. After Godzilla is temporarily knocked down after being hit by Mothra's wing, the humans run into the giant basket, which is carried by Mothra and flies away. Godzilla escapes the island just in time before the island self-destructs. The humans also see that Yata is a native on Infant Island.
In Japan, the film was released on December 17 and sold approximately 3,450,000 tickets. It was re-released on July 22, 1972 and sold approximately 760,000 tickets.