Is it possible to change the name of a Site Collection? I'm using SharePoint Online. It's just a test Site Collection so I can always delete it and create a new one.
If you are talking about the title of site collection then you can change it from site settings and title.
But if you talking about the changing the name in url then it is not possible today. You have to delete it and recreate it.
Note: i was in a session @ignite about SharePoint admin center and they mentioned this feature will be in pipeline and available next year. they tease with the image.