The most powerful king of the various Etruscan city-states.
Mepe-Umaglesi 'Most High King' was a predicate of the Georgian Orthodox Mepe-Mepeta ('King of Kings')
In Lithuania, the title of "Didysis Kunigaik?tis" is more accurately translated as "high king", although it is traditionally rendered as "Grand Duke"
In ancient Sumer, the rulers of all Sumer held the title of "Nam-Lugal" (High King)[1].
The Bretwalda was essentially the high king of the Anglo-Saxons, though the name is rarely translated as such. The Yang di-Pertuan Agong in Malaysia could probably be seen as a "high king", as he is selected from among nine Malay rulers (seven Sultans, a Raja, and a Great Lord) by election (through informal agreement, on a rotational basis). In practice, however, the term "high king" is rarely applied to the Yang di-Pertuan Agong, rather 'King'.
In C. S. Lewis's fictional Chronicles of Narnia, Peter was the High King of Narnia over Edmund, Susan and Lucy by virtue of being the eldest. He was also the High King over all Kings of Narnia, from the first to the last.
In J. R. R. Tolkien's works, mainly The Silmarillion, there was a succession of High Kings of the Noldor exiled in Middle-earth, beginning with Fëanor and culminating in Gil-galad's reign. Ingwë, leader of the Vanyar, is also referred as the High King of the Eldar, while Manwë is also sometimes titled High King of Arda. Thingol is acknowledged as high-king of Beleriand by Fingolfin. In the Third Age, the rulers of Arnor were known as "High King," including Aragorn, as King Elessar.
In Lloyd Alexander's Chronicles of Prydain, there is a line of High Kings of Prydain who are descendants of a royal family who came from the Summer Country in order to oppose Arawn. The High King throughout the series is Gwydion's father Math, who is then succeeded by Gwydion and later Taran in the final novel of the series, The High King.