White tie, also called full evening dress, is the most formal evening dress code in Western fashion.

The dress code's origins can be traced to the end of the 18th century, when high society men began abandoning their breeches, lacy shirts and richly decorated evening coats for more austere tailcoats in dark colours, a look inspired by the country gentleman.

Fashionable dandies like Beau Brummell popularised a minimalist style in the Regency era, tending to favour dark blue or black tailcoats, often with trousers instead of breeches, and white shirts, waistcoats and cravats.

By the 1840s the minimalist black and white combination had become the standard evening wear for upper class men.

Despite the emergence of the dinner jacket (or tuxedo) as a less formal and more comfortable alternative in the 1880s, full evening dress remained the staple.

Women wear a full-length evening dress, with the option of jewellery, a tiara, a pashmina, coat or wrap, and small evening bags. The waistcoat should not be visible below the front of the tailcoat, which necessitates a high waistline and (often) braces for the trousers.

As one style writer for GQ magazine summarises "The simple rule of thumb is that you should only ever see black and white not black, white and black again".Some invitations to white-tie events, like the last published edition of the British Lord Chamberlain's Guide to Dress at Court, state that national costume or national dress may be substituted for white tie.Throughout the Early Modern period, western European male courtiers and aristocrats donned elaborate clothing at ceremonies and dinners: coats (often richly decorated), frilly and lacy shirts and breeches formed the backbone of their most formal attire.At the turn of the 20th century, white became the only colour of waistcoats and ties worn with full evening dress, contrasting with black ties and waistcoats with the dinner jacket, an ensemble which became known as black tie.From the 1920s onward black tie slowly replaced white tie as the default evening wear for important events, so that by the 21st century white tie had become rare.White tie now tends to be reserved for royal ceremonies—especially state dinners—and a very select group of social events such as Commemoration balls at Oxford and Cambridge universities and very formal weddings.