Question: I've seen that both 'hoi polloi' and 'the hoi polloi' can be used. Does anyone know which is more accepted or correct? Or are they the same?

Answer: 
In its definition of *[hoi polloi](http://unabridged.merriam-webster.com/unabridged/hoi%20polloi)*, M-W Unabridged notes:

> 
> Since *hoi polloi* is a transliteration of the Greek for “the many,”
>  some critics have asserted that the phrase should not be preceded by
>  the. They find “the hoi polloi” to be redundant, equivalent to “the
>  the many”—an opinion that fails to recognize that *hoi* means nothing
>  at all in English. Nonetheless, the opinion has influenced the
>  omission of *the* in the usage of some writers.
> 
> 
> But most writers use *the*, which is normal English grammar.
> 
> 
> 

In its example usage sentences, M-W Unabridged gives examples of both usages:

> 
> "strain so hard in making their questions comprehensible to *hoi
>  polloi*" — S. L. Payne
> 
> 
> "burlesque performance … for the *hoi polloi*" — Henry Miller
> 
> 
>
From [this](http://www.phrases.org.uk/meanings/183475.html) article it seems like an article (the) is necessary because it translates directly to 'the many'