For other uses see Ceremony (disambiguation).
thumb|right|250px|Part of the ceremony of the Changing of the Guard in Whitehall, London.A ceremony is an activity, infused with ritual significance, performed on a special occasion.
Sometimes, a ceremony may only be performed by a person with certain authority. For example, the opening of the United Kingdom Parliament is presided over by the Sovereign (Her Majesty Queen Elizabeth II). The naming and launching of a warship will be under the supervision of its captain or a higher-ranked naval officer. A wedding will be performed by a priest or a Civil Celebrant, as in Australia. The President of the United States is customarily sworn in by the Chief Justice of the United States, and the British sovereign is always crowned by the Archbishop of Canterbury.
Other, society-wide ceremonies may mark annual or seasonal or recurrent events like:
Other ceremonies underscore the importance of irregular special occasions, such as:
In some Asian cultures, ceremonies also play an important role, for example the tea ceremony.
Both physical and verbal components of a ceremony may become part of a liturgy.