Class III

Class III may refer to:
 * Class III antiarrhythmic
 * Class III β-tubulin
 * Class III electrical appliance
 * Class III gaming
 * Class III NFA firearm
 * Class III PI 3-kinase
 * Class III railroad
 * Luminosity class III (giant) star in the Yerkes or MK-system
 * Pesticide Toxicity Class Class III
 * World Health Organization
 * United States Environmental Protection Agency
 * EU