If you'd like to hide titles from your viewing activity, follow the steps below.
Sign in to Netflix.com.
Select the profile you'd like to edit the viewing history for.
Click on the Account option.
Under My Profile, select Viewing activity.
On the My activity page, click on the icon next to the episode or title you wish to hide (if you are hiding an episode, you will be given the option to hide the entire series).
If you would like to hide all of your viewing activity, select the Hide all option at the bottom of the page. You will be prompted to confirm that you wish to hide all viewing history.
Once you hide a title from your viewing activity, it will no longer display as a title you have watched, and you cannot re-add it unless you play that title again. Please note that it can take up to 24 hours for the hidden title to be completely removed from all your devices. Titles cannot be hidden on Kids profiles.