That’s a very important setting for a surprise party.
Short Answer: Yes, you can hide the guest list, but only if you set the event’s privacy to ‘Private’. You cannot hide the guest list on a ‘Public’ event.
This setting controls the visibility of the text-based list of attendees, which is exactly what you need to keep confidential for a surprise.
When you are creating your Facebook event, the first crucial step is to select ‘Private’ under the privacy options. After you do this and are filling in the other details, look for an ‘Event Settings’ or ‘More Options’ section. Inside, you should find a simple toggle switch or a checkbox labelled ‘Show guest list’. You must turn this toggle off. This will prevent anyone you invite from being able to see the full text list of other invitees, protecting everyone’s privacy and, most importantly, keeping the secret.
Cheers,
Jeff