Taylor Swift and Travis Kelce's wedding has fans feeling the love ... because a crowd of Swifties turned the sidewalk outside Madison Square Garden into one giant singalong of "Love Story."

TMZ caught dozens of fans gathered outside the venue, swaying and belting out the hit together while hoping to catch a glimpse of any of the A-list guests. Check the video ... this is what it's all been leading up to for the Swifties.

As we have reported, the celebration inside MSG is straight out of a fairytale ... with an elaborate wedding theme transforming the iconic arena into the perfect backdrop for Taylor and Travis' own happily ever after.

The guest list may be exclusive ... but outside, Swifties were more than happy to create their own reception -- proving they don't need an invitation to keep the party going. And for everything happening outside the Garden, you can follow along on a live stream covering all the wedding-day action.

Romeo and Juliet never had a crowd like this!