Hoi Polloi
(Gk) The People
The general public, the populace, what Bertie Wooster often referred to as the 'Many headed'.
As Kingsley Amis, (another member of the Gentlemen's pantheon) has pointed out, hoi is Greek for the thus use of a supernumerary definite article is both redundant and incorrect.
The correct usage will mark you as a pedant, the incorrect as a Tory. We leave you to make your own choice.