A wedding is a ceremony in which two people are united in marriage. Wedding traditions and customs vary greatly between cultures, ethnicities, races, religions, denominations, countries, social classes, and sexual orientations. Most wedding ceremonies involve an exchange of marriage vows by a couple; a presentation of a gift (e.g., an offering, rings, a symbolic item, flowers, money, or a dress); and a public proclamation of marriage by an authority figure or celebrant. Special wedding garments are often worn, and the ceremony is sometimes followed by a wedding reception. Music, poetry, prayers, or readings from religious texts or literature are also commonly incorporated into the ceremony, as well as superstitious customs.

Some cultures have adopted the traditional Western custom of the white wedding, in which a bride wears a white wedding dress and veil. This tradition was popularized through the marriage of Queen Victoria. Some say Queen Victoria's choice of a white gown may have simply been a sign of extravagance, but may have also been influenced by the values she held which emphasized sexual purity.

The use of a wedding ring has long been part of religious weddings in Indian sub-continent, Europe and America, but the origin of the tradition is unclear. One possibility is the Roman belief in the vena amoris, which was believed to be a blood vessel that ran from the fourth finger (ring finger) directly to the heart. Thus, when a couple wore rings on this finger, their hearts were connected. Historian Vicki Howard points out that the belief in the "ancient" quality of the practice is most likely a modern invention. In the United States, a groom's wedding band has not appeared until the early 20th century, while in Europe it has been part of the tradition since the ancient Romans, as witnessed by the jurist Gaius.

The exit from the wedding ceremony is also called the "send off" and often includes traditional practices; for instance, in Ethiopian weddings, newlyweds and the rest of the wedding party bow and kiss the elders' knees. In most of the Western world, as well as in countries such as India and Malaysia, the send off often includes the practice of throwing rice (a symbol of prosperity and fertility) or other seeds at the newlyweds. Despite popular belief, using uncooked rice for this purpose is not harmful to birds. In several cultures, people toss shoes instead of rice.

The wedding ceremony is often followed by a wedding reception or wedding breakfast, in which the rituals may include speeches from a groom, best man, father of a bride and possibly a bride, the newlyweds' first dance as a couple, and the cutting of an elegant wedding cake. In recent years traditions have changed to include a father-daughter dance for a bride and her father, and sometimes also a mother-son dance for a groom and his mother.

In some countries there are restrictions on where a wedding may take place, for example before the Marriage Act 1994, marriages in England and Wales could only take place in authorized religious buildings or civil register offices, but the Act extended the options available to allow weddings in other "approved premises". Cretney identified a wide range of venues which sought approval after the implementation of this legal change, including funeral homes, hotels, stately homes, baseball fields, football grounds, basketball courts, beaches, a cemetery's chapel, town halls, museums, performing arts centers, health clubs, urban parks and former warships. Related outdoor locations could also be approved for weddings after the Marriages and Civil Partnerships (Approved Premises) (Amendment) Regulations 2022 were adopted.

Music played at Western weddings includes a processional song (e.g., the Wedding March) for walking down the aisle, either before or after the marriage service. An example of such use is reported in the 1878 wedding of Nora Robinson and Alexander Kirkman Finlay.

The "Bridal Chorus" from Lohengrin by Richard Wagner, commonly known as "Here Comes the Bride", is often used as the processional. Wagner is said to have been anti-Semitic, and as a result, the Bridal Chorus is normally not used at Jewish weddings. UK law forbids music with any religious connotations to be used in a civil ceremony.