The Periodic Table Universe features a wide cast of characters. Every character is either an element, compound or a scientific or historical reference.

Characters of the Periodic Table Universe
DropletMolly-QLProfessor Humphry Heisenberg OttoDr. Ruby DiumLord KryptonProfessor StratusFirelingPrincess Cara BonnieLos NinosSobekCaptain Salty PeterSill E. ConTree Frogs • Fire Grunts • Tachyon Gang • Iron • Nitrogen • Lord Radon • Plutonium Overlord • Emperor Fritz