Why do English speakers call him Jesus instead of Joshua?

There are in fact records of multiple persons with that name, and in fact, there are several of them in the Bible. For starters, “Jesus” is not the name that the man would have been known by in his lifetime. “Jesus” is an Anglicization of Iēsūs, a Latinization of the Greek “Ἰησοῦς” (Iesous), which is itself the Greek form of the name Hebrew/Aramaic “Yēshūăʿ”.

Jesus, the son of Joseph, would have been known to those around him as “Yeshua ben Yoseph”. To add another layer to this, Yeshu’a (יֵשׁוּעַ) is a form of the name “Y’hōshūă” (יְהוֹשֻׁעַ). Yehoshua in turn gets Anglicized as “Joshua”, which leads eventually to the culmination here, namely that “Jesus” and “Joshua” are, through a convoluted path, the same name. The name itself derives from “God [Jah] is salvation”.

There are in fact several persons then who bear this name in the Bible. The second-most famous of course would be Joshua, of “The Book of Joshua”, and one of the great heroes of Jewish history, leading them into the promised land and defeating the Canaanites.

In this light, giving your child the name of “Yeshua” or “Yehoshua” is not unlike the old practice in early America where the Founding Fathers provided inspiration for names of children like Washington Irving, or perhaps something like the common Armenian name of Haik, which harks back to their mythical founding figure.

Many other Joshuas (Yeshua/Yehoshua) existed in those times, such as the Biblical figure of the High Priest in the Book of Zechariah, as well as more tangible evidence such as tombstones found on various graves in the region from the period. Ilan and Hünefeld provide a number more examples from various literature of the period such as Rabbinical writings and Josephus.

Some of you will no doubt remember the minor news item from a decade ago around the ‘Talpiot tomb’ in Jerusalem which was revealed to have the names of Jesus, Mary, and Joseph present on ossuaries (it had been discovered years prior, but that year Discovery Channel did a nice sensationalist pseudo-history piece on it).

Needless to say, controversy surrounds it, but at the very least a strong argument against it is the simple fact that none of the names present were particularly unique for the time. There are even multiple examples of “Yeshua‘ bar Yehosep” and similar derivations in epigraphy that most certainly don’t refer to Jesus.

A similar ossuary also exists bearing “Ya’akov bar Yosef achui de Yeshua” (“James, son of Joseph, brother of Jesus”) on it, and although there is strong suspicion surrounding it as being a more modern fraud, in any case, even if ‘legitimate’ it similarly can be explained by the commonality of such names.

In sum, the name was likely a fairly common one in Jewish communities of antiquity, but through the quirks of transliteration, the specific form of ‘Jesus’ has passed down as being fairly unique and stands out from the Joshuas, even though they wouldn’t have at the time, and doesn’t in the actual epigraphic evidence of the period.