Android O would be called as Android Oreo - Android Oreo.

The suspense of the Android 8.0 is now  out, that the new Android OS (8.0)will be called as Android Oreo. There was a published post on Google+ teasing about the new Android OS, the video was deleted immediately but the Android Police took the screenshot of the post. The video file was named as  "GoogleOreo_Teaser_0817_noDroids (1).mp4  ".

But there was many possibilities like Octopus and Orangina, we can hear the naming of the new Android OS on 21st August, which is three days away. And see whether Android O will be Android Oreo or Android Orange.