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 Kunigaikštis" 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).
The Bretwalda was essentially the high king of the Anglo-Saxons, though the name is rarely translated as such.
The Yang di-Pertuan Agong (literally Supreme Lord) in Malaysia could probably be seen as a "high king", as he is elected from among nine Malay rulers of the states (seven Sultans, a Raja, and a Yang di-Pertuan Besar-literally Great Lord) by the Conference of Rulers (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".
The "maharaja" (Indian) could possibly be rendered as "high king", although the literal meaning is closer to "great king".
"Taewang," meaning "greatest of kings," was used by the later rulers of the Korean kingdom of Koguryo (and Silla, albeit to a rarer extent) to rank themselves as equals to the Chinese Emperors or to express suzerainty over surrounding states, particularly during the Three Kingdoms Era. "Daewang" ("great king") was used by rulers of other kingdoms and subsequent dynasties, including Baekje, whose king assumed the style of "Daewang Pyeha" ("His Imperial Highness the Great King") by the reign of Kimg Mu (600-640 AD) at the latest. However, after the Mongol Invasions of Korea, these rulers remained technically subordinate to the Mongol Empire and later China until King Gojong declared the Korean Empire in 1897 and assumed the title of "Hwangje," or Emperor (the Korean rendition of the Chinese "huang di").
In C. S. Lewis's epic fantasy, The Chronicles of Narnia, Peter Pevensie was the High King of Narnia over the younger Edmund Pevensie, by virtue of being the eldest, and his brother and sisters, Susan Pevensie and Lucy Pevensie were King and Queens under his monarchy. He was also the High King over all Kings of Narnia, from the first to the last. Aslan, the deity and the Great Lion of Narnia, is described as being "the High King above all High Kings", meaning He is the highest King over all rulers of Narnia.
In Lloyd Alexander's Chronicles of Prydain, there is a line of High Kings of Prydain (a fictionalized version of Wales) 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.
In Bethesda SoftworksThe Elder Scrolls The high king is the highest authority in the Province of Skyrim and theoretically the high king of Alinor is also the highest authority of the Summerset Isle (later renamed Alinor).