The parade attracted groups of thousands to a route from Parnell Square to Temple Bar in for an event many believed a Galway arts ensemble had organised.
However, this was not the case. In fact, a website called My Spirit Halloween organised the event.
My Spirit Halloween is a Pakistan-hosted website that creates AI-generated news.
Only after Halloween celebrators arrived did people realise that the website made up the whole thing.
It falsely advertised the parade, which made it onto multiple social media platforms.
Many people arrived at the location dressed up, ready for what they thought was the place of the parade, leading the Irish police force, Gardaí, to disperse the gathering.
On social media platform X, they shared a post: "Please be advised that contrary to information being circulated online, no Halloween parade is scheduled to take place in Dublin City Centre this evening or tonight.
"All those gathered on O'Connell Street in expectation of such a parade are asked to disperse safely. Thank you."
The crowds of people waiting for the celebration that was promoted to be from 7 pm to 9 pm caused distribution for two of the city's tram lines. Luas tram network's Red and Green lines were out of service for half an hour.
Sinn Fein councillor Janice Boylan described the situation as "really sad."
She added: "Everyone is trying to have a fun and safe Halloween. Having a parade sounded really good. I know an awful lot of people turned up. It's a terrible pity."
The My Spirit Halloween website has appeared to have now been taken down.
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