When I first noticed the name of the actor Shia LaBeouf in the media, a year or two ago, I assumed that it was a stage name, and I thought that it was a pointedly funny one: combining the name of a branch of Islam with a caricature of French!
I have since found out several things. One is that Shia LaBeouf is the actor’s real name; another that the first name is pronounced to rhyme with Mariah, not Maria, and that it was given to him by his Jewish mother, supposedly (according to Wikipedia) meaning “gift from God”.
I believe there is some confusion there with the name Shai (שי), which does mean “gift.” Shia’s mother’s name is Shayna, indicating a Yiddish-speaking background. And a name with the same pronunciation as the actor’s (Shaye in the YIVO transcription) was quite common during my Jewish childhood in Poland. In Polish it was written Szaja, but in Yiddish is most typically written in the Hebrew form ישעיה (Yeshaya), a variant of ישעיהו (Yeshayahu), the Hebrew name (meaning something like “salvation by God”) of the prophet Isaiah.
As regards LaBeouf, it turns out that Shia’s father is Cajun, evidently descended from a Frenchman with the not uncommon surname of Lebœuf. For a long time Cajuns were a largely illiterate society, and when schooling came to them it was in English, not French, so that when they needed to spell their French surnames they had to do so without knowing how to read or write French.
French surnames, among Cajuns and elsewhere, often end with the phoneme /o/. There are a great many ways in which this ending can be spelled: -o, -od, -os, -ot, -au, -aud, -aut, -ault, -aux, -eau, -eaux, -eaulx. I have not made a survey, but it’s my guess that the most common ones are -eau and -ot, because these ending represent diminutives that were productive in Middle French (analogous to the English -kin or -kins) and are still occasionally productive: Charlie Chaplin is known in French as Charlot (and my wife likes to call me Cobykins).
For some reason Cajuns seem to favor -eaux, perhaps because of the frequent presence of Bordeaux in written media. There are countless Cajun jokes about two characters named Boudreaux and Thibodeaux. The latter would, in France or Canada, be known as Thibaudot or Thibaudeau, a diminutive of Thibaud. The former name I have seem mainly as Boudrot. But jokes about Boudrot and Thibaudot wouldn’t be as funny as ones about Boudreaux and Thibodeaux, would they?