The original name was Yehoshua (Jehoshua in standard English transliteration, which is actually used in the KJV for Joshua in Numbers 13:16 and I Chronicles 7:27 (with a final H in the latter case).
"Clippings" of the initial two syllables produced Y[sup]eh[/sup]oshua and Ye[sup]ho[/sup]shua (Joshua and Jeshua), respectively the name of the son of Nun who was Moses's lieutenant and successor in leading the last phase of the Exodus, and the high priest after the Return from Exile. The latter name is the one which Gabriel indicated was to be the name of Mary's Son (Luke 1:31, Matthew 1:21) and which Mary and Joseph named Him (Matthew 1:25, Luke 2:21 -- BTW, since this naming took place at his circumision on the eighth day of his life, January 1 is celebrated in our church as the Feast of the Holy Name of Jesus.)
Adaptation of Hebrew names into Greek often involves the rendering of a final syllable ending in a vowel, with or without an -H, as that vowel followed by an -S. Some older Catholic and Orthodox Bibles, following the Greek, render the first two major prophets as the Books of Isaias and Jeremias for that reason. And John the Baptist's father is in older translations given as Zecharias, even though his name was identical to the minor prophet Zechariah, for the same reason.
Accordingly, Yeshua in Hebrew and Aramaic becomes Iesous in Greek, Jesus (with a vocative case of Jesu) in Late Latin, where the J was adopted in place of I for the Y sound, and Jesus in most continental languages and English (pronounced according to the local custom for a J sound -- it's /YE-sus/ in German, and /hay-SOOS/ in Spanish, even though spelled "Jesus" as in English, the only language to give the /dzh/ phoneme to J to produce our /JEE-zus/ pronunciation. (None of the forms between slashes are intended to ridicule, of course, but to define the sounds made in pronouncing the written name.)