The bow tie is a fashion accessory, popularly worn with other formal attire, such as suits or dinner jackets. It consists of a ribbon of fabric tied around the collar in a symmetrical manner such that the two opposite ends form loops. Ready-tied bow ties are available, in which the distinctive bow is sewn into shape and the band around the neck incorporates a clip. The traditional alternative, consisting of a single strip of cloth, may be known as a "self-tie" bow tie to distinguish it. Bow ties are most commonly worn by men.

It originated among Croatian mercenaries during the European wars of the 17th century: the Croats used a scarf around the neck to hold together the opening of their shirts. This method was soon adopted (under the name Cravat) by the upper classes in France (then a leading country in the field of fashion) and flourished in the 18th and 19th centuries. The famous French writer Honor? de Balzac even wrote a book on the subject.

Towards the end of the 19th century the free ends of the bow tie grew longer, and the necktie was born, and the bow tie slowly went out of fashion in all but the architecture classes where it has remained a defining item of the architect's uniform.

Although the necktie proves most prominent in today's society, being seen at business meetings, formal functions and sometimes even at home, the bow tie is making a comeback with fun-formal events such as dinner and cocktail parties, and nights out on the town. It is also still much more common to wear a bow tie with a tuxedo than it is to wear a necktie with one?previously the bow tie was the only proper neckware for a tuxedo.

The dress code of "black tie" requires a bow tie, though, paradoxically, it need not always be black these days. Most military mess dress incorporates a bow tie, which must always be of the self-tie type. For a military officer to wear a clip-on bow tie with mess-dress or dinner-jacket is regarded as a faux-pas, and in many regiments the offender will be required to purchase a significant quantity of champagne for his fellows, by way of a fine.

Edgar de Evia used to quote Oscar Wilde saying:

"Learning how to tie a bow tie really well is the first important step in life."

Many, including Robert Denning learned this skill from him.

Bow ties are commonly seen in popular culture as items of sophistication, such as those worn by fictional spy James Bond. However, they have also been adopted into the "uniform" of clowns and male strippers, and such associations have lent bowties a less serious image.

When choosing a bow tie that is not pre-tied (the "self-tie" bow tie), two main shapes are available - the "bat wing", which is parallel-sided like a cricket bat, or the "thistle", sometimes known as the butterfly. An example of each can be seen to the left. Which is worn is a matter of personal preference. Some other shapes do exist, for instance with pointed tips at both ends. Both of the bowties shown on the left are of the double-ended type, with both ends shaped; occasionally one still sees bowties of the single-ended type, in which only one end flares out to give the batwing ot thistle shape, and the other remains thin. These are less common than they used to be, as to tie them requires careful consideration, to ensure the broader end finishes in front of the thinner one.