This is a list of currently enthroned monarchs and lifelong leaders sorted by length of service.

Note that this is not a list of the longest-serving heads of state; for example, Emir Saqr bin Mohammad al-Qassimi is not the head of a sovereign country. This list also excludes rulers whose status as a true monarch is unknown. For example, Tenzin Gyatso, 14th Dalai Lama, has been the enthroned ruler of the exiled Tibetan government since November 17, 1950, which would have placed him above Elizabeth II. However, his position as a monarch remains controversial. Also, this list does not include monarchs of deposed monarchies such as Otto von Habsburg who, as the oldest son of Emperor Charles I of Austria, has claimed the Austro-Hungarian throne from April 1922 to the present (a 'reign' of over 87 years).

The list

Note: The table can be sorted alphabetically, chronologically or numerically using the File:Sort none.gif icon.