Yohanan, Yochanan and Johanan are various transliterations to the Latin alphabet of the Hebrew male given name יוֹחָנָן (Yôḥānān), a shortened form of יְהוֹחָנָן (Yəhôḥānān), meaning "YHWH is gracious".
The name is ancient, recorded as the name of Johanan, high priest of the Second Temple around 400 BCE. It became the most popular Christian given name in reference to either John the Apostle or John the Baptist.
In the Latin Vulgate this was originally adopted as Iohannes (or Johannes – in Latin, J is the same letter as I). The presence of an h, not found in the Greek adaptation, shows awareness of the Hebrew origin. Later editions of the Vulgate, such as the Clementine Vulgate, have Ioannes, however.
The anglicized form John makes its appearance in Middle English, from the mid-12th century, as a direct adaptation from Medieval Latin Johannes, the Old French being Jean. The feminine form Joanna is also biblical, recorded in the form Ἰωάννα as the name of Joanna, wife of Chuza.
The form Johanan, even closer to the Hebrew original than Latin Johannes, is customarily used in English-language translations of the Hebrew Bible (as opposed to John being used in English translations of the New Testament), in a tradition going back to Wycliffe's Bible, which uses John when translating from the Greek (e.g. of John the Baptist in Mark 1:4), but Johannan when translating from the Hebrew (as in Jeremiah 40:8).