Check the Contacts app and search for the missing contact
Open Phone app and check Recents or Favorites
Verify the correct account is enabled in Settings > Contacts > Accounts
Turn Contacts sync off and back on for iCloud, Gmail, Outlook, or other accounts
Sign in to iCloud.com and check whether the contact exists there
Restore contacts from iCloud.com if available
Check if contacts are hidden by a contact group or account filter
Restart the iPhone
Update the iPhone to the latest iOS version
Restore contacts from an iCloud backup if needed
Restore contacts from a computer backup using Finder or iTunes
Check other devices signed into the same account for the missing contact
Re-add the contact manually if no backup or sync copy exists