Notebooks for OneNote Online are on OneDrive. If you no longer need the notebook you can delete it. If there’s a chance you’ll want to use it again later, you can keep the notebook and, from the OneNote for desktop app, either or change who can view or edit it.
Before deleting a notebook that you’ve shared with others, let everyone who has permission to view or edit the notebook know that you’re planning to remove the notebook, so they don’t lose their work.
Important: Deleting a notebook is permanent. After you delete a notebook, you will not be able to recover it.
Open OneDrive and find the notebook in your list of files (it’s likely in Files > Documents).
Note: You might need to navigate to a different folder if the notebook was initially saved to a folder other than Documents.
Navigate to the OneNote notebook that you'd like to rename, right-click it, and then select Delete.
I still see the notebook after deleting
After you delete the notebook, it might still show up in your list of notebooks online. If you prefer a cleaner list of only the notebooks you use, you can open the OneNote for desktop app and remove the notebook from your list of notebooks. To do this:
Open OneNote for desktop and go to your list of notebooks.
Right-click the notebook name, and then click Close this Notebook.