To begin, log into your Facebook account, if you haven't logged in already.

Click the down arrow at the top right of any Facebook page, click Settings & Privacy, then click Activity Log.

In the left side of your activity log page and under Activity types, scroll down to the bottom and click on Logged actions and other activity.

Next, scroll down and select Videos You've Watched.

Now, you should see a list of all your past watched videos. If you want to delete a specific watched video, click on the three-dots icon next to it, then click Delete.

To delete all watched videos at once, click Clear Video Watch History link.

In the popup window that appears, click Clear Videos Watch History.

Open the Facebook app, then log into your Facebook account, if you haven't logged in already.

Tap the three lines icon, then scroll down and tap Settings & Privacy.

Next, tap Settings.

Scroll down to Your Information section and tap Activity Log .

Scroll down again and tap the down arrow next to Logged actions and other activity to expand the menu list, then tap Videos you've watched.

To delete any video from the watch history page, tap the three dots icon next to it, then tap Delete at the bottom.