Kyrillos is the Greek form of Cyril, from kyrios meaning “lord” or “master.”
Kyrillos is the ancient Greek form of Cyril, derived from the Greek word kyrios, meaning "lord" or "master." The name carries an august weight that stretches back to the early Christian world, where it was borne by one of history's most consequential linguists and missionaries. Saint Cyril of Thessaloniki, alongside his brother Methodius, undertook the monumental ninth-century task of evangelizing the Slavic peoples — and to do so, invented an entirely new writing system.
The Glagolitic script he devised was later adapted into the Cyrillic alphabet that still carries his name today, making Kyrillos perhaps the only name permanently embedded in the writing systems of hundreds of millions of people. In the Eastern Orthodox and Eastern Catholic traditions, Kyrillos remains the living form of the name, used widely across Greek, Coptic, and Ethiopian Christian communities. Several Coptic Popes of Alexandria have carried the name, cementing its status as one of the great ecclesiastical names of the Eastern Church.
Its root in kyrios also connects it to the New Testament Kyrie eleison — "Lord, have mercy" — giving it a liturgical resonance that purely secular names cannot claim. In contemporary usage, Kyrillos sits at an interesting crossroads: rare enough in Western countries to feel distinctive and exotic, yet deeply rooted in living traditions for Greek Orthodox and African Christian families. Parents who choose it often seek a name that honors heritage while carrying genuine historical gravity — a name whose story, quite literally, changed how a third of the world writes.