The Delta Theta III entity was an entity that lived on the planet Delta Theta III.
The entity, who was perceived as a god by James T. Kirk and Spock, oversaw the evolution of a race of saurian aborigines that also inhabited the planet. It talked Ari bn Bem out of disassembling himself as punishment for his actions. (TAS: "Bem")
The entity was voiced by Nichelle Nichols.