Critics mostly agree that Wilde's Dorian Gray was based, at least in part, on Wilde's friend, the beautiful working-class poet John Gray. The name 'Dorian' is taken as a way of signalling 'Hellenic' qualities in the character; even, perhaps, as a synonym for 'homosexual'. This is possible, of course. The Dorians were one of the four 'tribes' of Greeks; and what's distinctive about them -- in contrast to the Ionians, for instance -- is their affinity with Sparta, as a place and as a nexus of values. Herodotus records the Dorians as invading Greece around 1100 BC, sedttling in the Peloponnese: 'the people they displaced gathered at Athens under a leader Ion and became identified as "Ionians". Most conspicuous among the Dorians were the people later known as Lacedaemonians, or Spartans, one of whose archaic legendary kings was named Dōrieus'.
We don't usually think of The Picture of Dorian Gray as being a novel about a specifically Spartan ethos and ethnis; but perhaps we should.