Western dress codes are a set of dress codes detailing what clothes are worn for what occasion that originated in Western Europe and the United States in the 19th century. Conversely, since most cultures have intuitively applied some level equivalent to the more formal Western dress code traditions, these dress codes are simply a versatile framework, open to amalgamation of international and local customs. This versatility has made this scale of formality a practical international formality scale.

Classifications are divided into formal wear (full dress), semi-formal wear (half dress), and informal wear (undress). Anything below this level is referred to as casual wear, although sometimes in combinations such as "smart casual" or "business casual" in order to indicate higher expectation than none at all.

For both men and women, hats corresponding to the various levels of formality exist. As supplements to the standard dress codes, headgear can be worn, though certain settings have etiquette regarding this; for example, in Christian churches, traditional norms have enjoined the wearing of a headcovering (such as a veil or cap) by women, while men are prohibited from wearing a hat.

Ceremonial dress, military uniform, religious clothing, academic dress, and folk costume appropriate to the formality level are encouraged, but face-covering garments (niqab, hijab) are not always accepted. France outlawed the public use of burqas in 2010 and the European court of law seconded the law because "uncovered faces encourage citizens to live together" (see also burqa by country).

Typical events: Weddings, state dinners and affairs, formal balls, royal events, etc.

Typical events: Theatre opening nights, charity balls, etc. There is some variation in style depending on whether it is summer, spring, winter or fall. See black tie and stroller for more details.

Typical events: Diplomatic and business meetings, many social occasions, everyday wear

Casual wear encompasses business casual, smart casual, etc.