A mug is a sturdily built type of cup often used for drinking hot beverages, such as coffee, tea, or hot chocolate. Mugs often have handles and hold a larger amount of fluid than other types of cup. Usually a mug holds approximately 12 fluid ounces (350 mL) 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.

A mug can be made of various materials, depending on the use. The most often used material is ceramic. Travel mugs can be made of ceramic, stainless steel, or glass, and can be insulated or not.