Class 3

Class 3 may refer to:


 * BR Standard Class 3 2-6-0, British steam locomotive
 * BR Standard Class 3 2-6-2T, British steam locomotive
 * Classes of United States senators
 * L&YR Class 3, British 4-4-0 steam locomotive
 * SCORE Class 3, off-road racing trucks
 * The third class in terms of hiking difficulty in the Yosemite Decimal System
 * A class in US truck classification
 * Class 3, in the electrical Appliance classes
 * A contribution class in the National Insurance system in the UK