The video, featuring the song Happy by Pharrell, was posted online two days ago and has already clocked up over 30,000 hits.
Local girl Janine Kane, who owns Muriel's bar, came up with the idea after Belfast was voted the happiest city in the UK.
Belfast was found to be the UK city with the most smiles after analysis was carried out on over 100 million Instagram photos.
Initially, a few people Janine knew agreed to do it - but once she hit the streets she was shocked to find that even in the wind and rain passers-by were happy to strut their stuff for the camera at local attractions, including the Harland and Wolff's cranes and Queen's University.
Her friend's production company then put it together in just 24 hours and posted it on YouTube.
"The key thing is that we are able to laugh at ourselves, I don't think we poke fun seriously at each other," Janine said.
"I think we generally are very happy to laugh at ourselves and each other and I think that is kind of quite crucial in relation to our make up of people who come from Belfast and Northern Ireland."
The concept has already been done in other cities, but this video is a little unique due to the impromptu performances.
Emma-Rosa Dias, the video's producer, added: "We wanted it a bit more natural and no sort of dance routines or hair and make-up and do you know what?
"Not one person said to me 'Can we have five minutes to fix our hair or put lipgloss on?' They just danced and I couldn't believe it."
It is now hoped the video will show the world just how happy Belfast can be even when it's raining.