A drinking straw is a short tube used for transferring a liquid - usually a drink from one location to another (such as from a cup, to one's mouth). A thin tube of plastic (such as polypropylene and polystyrene) or other material, straight or with an accordion-like living hinge.

Early paper straws had a narrow bore similar to that of the grass stems then in common use. It was common to use two of them, to reduce the effort needed to take each sip. Modern plastic straws are made with a larger bore, so only one is needed for comfortable drinking.

One particular advantage of using a straw when drinking is the reduction of tooth decay. Many soft drinks have acidic properties, and using a straw reduces the liquid contact with the teeth, reducing tooth decay and the risk of cavities.