John is the most popular and regular name in English. The etymology in English comes from Middle English John, Johan, Johannes, from Anglo-Norman Jehan, Johan, and also Old English Iohannes, both from Late Latin Iōhannēs, variant of Latin Iōannēs, from Koine Greek Ἰωάννης (Iōánnēs), from Biblical Hebrew יוֹחָנָן (Yôḥānān), which means God is gracious

John is a popular name due to two popular saints, John the Baptist and the apostle John. The name has since been chosen as the religious name for a vast number of emperors, kings, popes, and patriarchs. In other words, the name John is popular because of the fact that it’s related to so many religious figures and is also used in the Bible so much, and as the Bible has a massive impact on Western countries, it’s not surprising that so many people chose that name.

The other variants of this name is German Iohannes, Greek Giannis, French Jeanne, Slavic Ivan