A coronation is the act of placement or bestowal of a crown upon a monarch's head. The term also generally refers not only to the physical crowning but to the whole ceremony wherein the act of crowning occurs, along with the presentation of other items of regalia, marking the formal investiture of a monarch with regal power. Aside from the crowning, a coronation ceremony may comprise many other rituals such as the taking of special vows by the monarch, the investing and presentation of regalia to the monarch, and acts of homage by the new ruler's subjects and the performance of other ritual deeds of special significance to the particular nation. Western-style coronations have often included anointing the monarch with holy oil, or chrism as it is often called; the anointing ritual's religious significance follows examples found in the Bible. The monarch's consort may also be crowned, either simultaneously with the monarch or as a separate event.

Once a vital ritual among the world's monarchies, coronations have changed over time for a variety of socio-political and religious factors; most modern monarchies have dispensed with them altogether, preferring simpler ceremonies to mark a monarch's accession to the throne. In the past, concepts of royalty, coronation and deity were often inexorably linked. In some ancient cultures, rulers were considered to be divine or partially divine: the Egyptian pharaoh was believed to be the son of Ra, the sun god, while in Japan, the emperor was believed to be a descendant of Amaterasu, the sun goddess. Rome promulgated the practice of emperor worship; in Medieval Europe, monarchs claimed to have a divine right to rule (analogous to the Mandate of Heaven in dynastic China). Coronations were once a direct visual expression of these alleged connections, but recent centuries have seen the lessening of such beliefs.

Coronations are still observed in the United Kingdom, Tonga, and several Asian and African countries. In Europe, most monarchs are required to take a simple oath in the presence of the country's legislature. Besides a coronation, a monarch's accession may be marked in many ways: some nations may retain a religious dimension to their accession rituals while others have adopted simpler inauguration ceremonies, or even no ceremony at all. Some cultures use bathing or cleansing rites, the drinking of a sacred beverage, or other religious practices to achieve a comparable effect. Such acts symbolise the granting of divine favour to the monarch within the relevant spiritual-religious paradigm of the country.

Coronation in common parlance today may also, in a broader sense, refer to any formal ceremony in relation to the accession of a monarch, whether or not an actual crown is bestowed, such ceremonies may otherwise be referred to as investitures, inaugurations, or enthronements. The date of the act of accession, however, usually precedes the date of the ceremony of coronation. For example, the Coronation of Elizabeth II took place on 2 June 1953, almost sixteen months after her accession to the throne on 6 February 1952 on the death of her father George VI.