Thousands of people had signed up to attend the Summer Safari Waterpark UK event that was advertised as coming to Belfast on 16 August.
The Facebook page revealed plans to tour 30 towns and cities across the UK in July and August.
The trading standards office said it could be a "data mining scam".
The Facebook page advertising the event now appears to have been removed.
It comes after a promotion for a non-existent tour based on the BBC's popular Total Wipeout series also proved to be fake.
Councils in Scotland and England have said they had received no notification of the events.
Belfast City Council have also confirmed it has received no application to hold the event.
The NI Trading Standards Service said that the event "appears to be similar" to other events that were advertised as taking place in Belfast last year but did not happen.
It warned that interacting with these pages could allow people to access personal information.
"Clicking a button to say you are 'interested' may seem harmless, but even though the creators of a Facebook event do not explicitly ask for personal details, they can comb through the profiles of those 'interested' or 'going' and pull personal data from their profiles without their knowledge.
"They can do with this data what they like, include selling these details on to online spammers or scammers.
"This is referred to as a data mining scam.
"Until the legitimacy of this individual event can be confirmed, as a precaution we would advise not to interact with it if you see it on the newsfeed."
A water park event that was advertised on social media could be a scam, the Northern Ireland Trading Standards Service has warned.