This article lists the 100 oldest living current or former state leaders whose age can be demonstrated beyond reasonable doubt. State leaders are defined to include heads of state (including representatives who act in their stead, generally a governor-general), heads of government and internationally recognized de facto leaders of sovereign states with significant international recognition. Leaders are not included if no reliable secondary sources have confirmed that the leader is alive within the last 10 years. The oldest living former state leader is Mustafa Ben Halim of the Kingdom of Libya at the age of 99 years, 348 days. Leaders currently in office are in bold on purple, with Elizabeth II of the United Kingdom being the oldest currently serving head of state.