In American English, a dress shirt, button shirt, button-front, button-front shirt, or button-up shirt — "work shirt", "business shirt", or "Oxford shirt" in British English — is a garment with a collar and a full-length opening at the front, which is fastened using buttons or shirt studs. A button-down or button-down shirt is a dress shirt with a button-down collar – a collar having the ends fastened to the shirt with buttons.

A dress shirt is normally made from woven cloth, and is typically accompanied by a tie or bow tie, jacket, suit, or formalwear, but a dress shirt may also be worn more casually.

In British English, "dress shirt" — "formal shirt" or "tuxedo shirt" in American English — means specifically the more formal evening garment, often with an embroidered decorative chest to be paired with a cummerbund, worn with black-tie dinner jacket or white-tie tailcoat. Some of these formal shirts have stiff fronts and detachable collars, either standing wing collar or fold-down collar, attached with collar studs.

Traditionally dress shirts were worn by men and boys, whereas women and girls often wore blouses, sometimes known as chemises. However, in the mid-1800s, they also became an item of women's clothing and are worn by both sexes today.

A shirt has several components:

Originally the collars and cuffs were detachable, held on by studs or buttons, for ease of tailoring and maintenance. This was because these had the most wear and got dirtier more quickly so need special washing and more frequent replacement in a time when laundering was very labor-intensive and difficult work to what were very expensive products prior to mass-manufacturing.

There are various styles of collar, which is the primary indicator of the formality of a shirt. Those discussed here are all attached collars, not styles specific to detachable collars. The very top button is number 1.

The less-common styles below were all once common, but have waned in popularity.