Opis (or Upis) was a Hyperborean maiden who with Arge accompanied Leto, Apollo and Artemis to Delos. According to some accounts she was raped by Orion (who was then killed by Artemis for the affront).

She may, however, have been a local goddess who came to be associated with Artemis, and this may account for her name meaning either 'reward' or 'punishment' (opis). Gods and goddesses reward or punish depending whether they are smiling or frowning on you.