Important: If you turned on iCloud for Keynote (in System Preferences on your Mac), deleting a presentation from iCloud removes it from iCloud and from all other devices and Mac computers that use the same iCloud account.
If you don’t know where the presentation is, locate it first.
Select the presentation, then do one of the following:
Drag the presentation to the Trash icon in the Dock.
Press Command-Delete on the keyboard.
To permanently remove the presentation from your computer, click the Finder icon in the Dock, then choose Finder > Empty Trash (from the Finder menu at the top of your screen).
If you don’t want to keep a new presentation you haven’t saved yet, close the presentation, then click Delete in the Save dialog that appears.
If you open an existing presentation, edit it, then decide you don’t want to keep any of your changes, you can restore the presentation to how it was when you opened it.