When a list is no longer needed in SharePoint, a site owner can delete it. If you delete a list by accident, you can restore it from the recycle bin.
Delete a list in the modern list experience
Go to the list you want to delete completely.
Click Settings and then click List settings.
In the Settings page, click Delete this list.
In the confirmation dialog, click OK.
Note: The steps above are for the modern list experience. For the classic list experience, follow the steps for the classic experience.
Delete a list in the classic list experience
Go to the list that you want to delete.
Select the List tab and then List Settings.
On the list settings page, select Delete this list, and then OK.
Note: If List Settings are disabled or Delete this list isn't on the list settings page, you may not have the necessary permissions to modify the settings or delete the list, contact your administrator.
Restore a list using the Recycle bin
Depending on how you or your admin has set up the site, you can restore the list from the SharePoint Recycle bin for up to 90 days.
For more on the Recycle bin, see Restore items in the Recycle Bin of a SharePoint site.
If you've cleared your SharePoint recycle bin, see how to restore from the Second-Stage recycle bin at Restore deleted items from the site collection recycle bin.