MUG may refer to:

• Macintosh User Group
• Male Un-bifurcated Garment, a technical term for Men's skirts
• 4-methylumbelliferyl-beta-D-glucuronide, a substrate used in the GUS reporter system
• The MUMPS User Group
• Multi User Game, another term for Multiplayer game
• The Medical University of Gdansk in Poland
• Double-stranded uracil-DNA glycosylase, an enzyme

A mug is a type of cup typically used for drinking hot beverages, such as coffee, hot chocolate, soup, or tea. Mugs usually have handles and hold a larger amount of fluid than other types of cup. Usually a mug holds approximately of liquid; double a tea cup . A mug is a less formal style of drink container and is not usually used in formal place settings, where a teacup or coffee cup is preferred. Shaving mugs are used to assist in wet shaving.