A T-shirt (or tee shirt) is a shirt which is pulled on over the head to cover most of a person’s torso. A T-shirt is usually buttonless, collarless, and pocketless, with a round neck and short sleeves. The sleeves of the T-shirt extend at least slightly over the shoulder but not completely over the elbow (in short-sleeve version).

A shirt that is either longer or shorter than this ceases to be a T-shirt. T-shirts are typically made of cotton or polyester fibers (or a mix of the two), knitted together in a jersey stitch that gives a T-shirt its distinctive soft texture. T-shirts can be decorated with text and/or pictures, and are sometimes used to advertise (see human billboard).

T-shirt fashions include styles for men and women, and for all age groups, including baby, youth, and adult sizes.

The T-shirt evolved from undergarments used in the 19th century, through cutting the one-piece “union suit” underwear into separate top and bottom garments, with the top long enough to tuck under the waistband of the bottoms. T-shirts, with and without buttons, were adopted by miners and stevedores during the late 1800’s as a convenient covering for hot environments.