The song was announced on twitter by Natalie Blinston, saying 'Love my girl's @kellyflint new track 91, can't wait for you Flintos to hear it!' after a month after the tweet went out, Kelly said that 'Natalie wasn't supposed to say anything but you know, the song is about me and Max when we first met each other as teens in 1991 and it was a sunny day and I just kept staring at him and looking into his eyes'.
Kelly then took to twitter on March 2, 2015 quoting the song: 'When we're under the sun, it's like 1991' and then 6 days later revealing the cover art and the full song on twitter.
The video was filmed in New York in an unknown location on March 2, 2015. On March 9, 2015, Kelly took to twitter to show a preview of the 91 music video. On March 9, 2015 she released the video, which got 20 million views in under 2 hours, making it a most views in under 24 hours winner.