Who is the narrator, can she or he read minds, and, more importantly, can we trust her or him?
Third Person (Omniscient)
Although we see the story mainly through the lens of Dorian's opinions, we also dip into the minds of other characters here and there, from Lord Henry to Mrs. Vane. We're able to see everyone's thoughts and perspectives, but that doesn't mean we have an objective, or even necessarily fair narrator—in fact, this narrator is super harsh sometimes (see "Tone" for more on this).
However, the narration is really thorough and complete... even if Wilde is snarky.