Saigo is a monster from the planet Kodon, that appeared in episode 38 of the original Ultraman series.
Living on the mysterious planet Kodon, Saigo apparently being the natural enemy of Kiyla is first seen battleing the space louse on the planets surface as observed by the Science Patrol from their jet, and after a long battle Saigo attempts to retreat after being blinded by Kiyla's eye flashes, into the undergrond but Kiyla grabs his tail, Saigo deataches the tail letting Kiyla fall and Saigo to flee. Later on when the Science Patrol had landed on Kodon's service Saigo comes up from the ground and attacks Ide and Hayata after their veichle had gotten grounded, the two unleash all their fire power on the beast covering it in dry ice were the beast shatters and dies.
- There are a few toys of Saigo.
- Saigo is one of several monsters Ultraman had never faced.
- Saigo's roar is reused for the monster Kingstron.