The Coronation of the Thai monarch is a ceremony in which the King of Thailand is formally consecrated by anointment and crowning. The ceremony is divided into two main events: the coronation rites and the celebration of the Assumption of the Residence. The coronation rites are a blend of Hindu and Buddhist traditions dating back several centuries. The rites included the purification bath of the king, the anointing of the king, the crowning of the king, and the investiture of the royal regalia, the royal utensils, and the royal weapons of sovereignty. The Assumption of the Residence is a private housewarming celebration by members of the royal family at the Grand Palace.

Historically, the coronation usually took place as soon as possible after the death of the previous monarch. This followed the custom that an unconsecrated king cannot bear certain regalia nor carry out any religious functions. However, in the last century this tradition has been replaced by a mourning period of about a year after the succession. The most recent coronation was held on 4 May 2019 for King Vajiralongkorn.