Open up the “Contacts” app and tap “Groups”
at the top left of the screen. Then scroll down to “All Facebook” at the very bottom and uncheck the item on the list. You can check any other group to make it visible, such as your iCloud contacts or other groups you may have enabled on your iPhone. Tap “Done” when ready.
The “Contacts” app will now hide the Facebook contacts in the main list view. Your other contacts should still be visible.
How to delete Facebook contacts from iPhone
Perhaps you’ve set up your Facebook account in iOS, while not knowing that a contact sync would populate your address book with lots of entries that might be undesirable. Luckily, this option is completely reversible.