Android O has been out for a while now in Beta form. It would be easy to think a device like the Note 8 which launches later this year would have this latest and greatest software on board, but that may not be the case. The phone was recently spotted in the HTML5Test database running Android 7.1.1. which is likely what we will see the phone launch with. It should be noted that Note devices in the past have always ran the same Android version as their S counterpart and that doesn't appear to be changing with the Note 8. That being said the device will almost surely get the O update at some point.
via HTML5Test