If you have a notebook on OneDrive that you no longer need, you can delete it. If there's a chance you'll want to use it later, you can keep the notebook and, from the OneNote desktop app (OneNote 2016), simply stop sharing it or change who can view or edit it.
Note: 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.
Open OneDrive and find the notebook in your list of files (It's likely in Files > Documents).
Place the pointer over the notebook tile or the file name (depending on which view you're using) and check the circle that appears.
Click Delete in the menu across the top of OneDrive.
Important: After you delete a notebook, you may not be able to recover it. Always back up important notes before you delete them.
After you delete the notebook, it might still show up in your list of notebooks. If you prefer a cleaner list of only the notebooks you use, you can open the OneNote desktop app and remove the notebook from your list of notebooks. To do this, open OneNote 2016, click the arrow next to your notebook name, find the notebook you deleted, right-click it, and choose Close This Notebook.