Orenthal

This given name is best known for being the first name of the retired American football player and actor O. J. Simpson, who was born in 1947 as Orenthal James Simpson. According to a 1968 interview with LIFE magazine, Simpson himself does not know the meaning and origin of his first name, telling the reporter that his aunt was the one who had named him and that she would only ever tell him that she had named him after a French or Italian actor.

However, it is possible that his aunt was either not telling him the (whole) truth or that Simpson had misremembered her words, as I have been unable to find a 1940s-era French or Italian actor whose given name or surname even remotely resembles Orenthal. In addition to this, research on FamilySearch learned that Orenthal was used as a given name in the United States long before Simpson: I came across men named Orenthal that were born in 1903, 1915, 1921 and so on.

Further research showed that a German surname of Orenthal once existed, as well as the rare Norwegian and Swedish surnames of Orendahl and Orendal. All of these surnames are probably locational surnames, since -dahl and -dal in Norwegian and Swedish surnames is usually derived from Norwegian and Swedish dal meaning "dale, valley", whereas -thal (and -tal) in German surnames is usually derived from Old High German tal meaning "valley".

If that is indeed true here, then the Norwegian and Swedish surnames are each probably a variant form of the surnames Arendahl and Arendal respectively, both of which refer to a place with that name (such as the city of Arendal in Norway or the suburb of Arendal in the Swedish city of Göteborg). The name of both of those places means "valley of eagles" and is ultimately derived from Old Norse ǫrn "eagle" and Old Norse dalr "dale, valley".
As for the German surname of Orenthal: I have been unable to find out from which place name the surname could have been derived. Perhaps we should take into account the possibility that it might be a patronymic surname instead, in which case it might possibly be derived from (or etymologically related to) the medieval German given name Orendel.

With that said: another surname that might be of note in regard to the given name Orenthal, is the Gaelic surname of Aurendal or Aurendel. It is likely a Gaelic (variant) form of Arundel, an English surname that is ultimately derived from either Norman French arondel meaning "little swallow" (as in, the bird) or from Old English harhune dell meaning "valley of the horehound flower".

To go back to O. J. Simpson's case again for a moment: if his aunt did indeed name him after an actor (or someone with an other profession in the entertainment industry), then this actor might not necessarily have been French or Italian (contrary to what she had later claimed), nor would his given name or surname necessarily have been Orenthal exactly. For example, it could be that she named Simpson after someone with the surname of Rosenthal, but swapped the places of the first two letters and dropped the 's'. If that is indeed true, then a 1940s actor that could have been a possible inspiration to her might have been Harry Rosenthal (c. 1893-1953), who was also a composer.

So, all in all, at this point in time it seems likely that the given name Orenthal ultimately goes back to a surname, but we might perhaps never know which one exactly.