- Charles III
- 15 total number
- United Kingdom ()
Most countries to be Head of State of simultaneously is 15, and was achieved by King Charles III (UK), on 8 September 2022.
Following Her Majesty’s Queen Elizabeth II’s passing on 8 September 2022, His Majesty King Charles III became the head of state for the following countries: Antigua & Barbuda, Australia, The Bahamas, Belize, Canada, Grenada, Jamaica, New Zealand, Papua New Guinea, St Christopher and Nevis, St. Lucia, St. Vincent and the Grenadines, Solomon Islands, Tuvalu and the United Kingdom.