Fans were left heartbroken when minutes after the doors were supposed to open for the matinee performance an announcement was made that the show and the evening performance were being rescheduled.
A statement by Aiken promotions said: "We regret to announce that both Little Mix shows at the SSE Arena will not take place today due to Jessie being unwell and not able to perform.
"Please hold on to your tickets - we hope to be able to make a further announcement on possible rescheduling later today."
They later added: "Sadly Jesy is unwell and unable to sing, and as a result both the matinee and evening shows are cancelled. Little Mix would like to apologise to their fans. Ticket holders should hold on to their tickets and await further news."
Doors were due to open for their first show on Thursday at 1.30pm and a second show was scheduled for 6.30pm.
The band had played the 3Arena in Dublin on Wednesday night and hours before the band were due to take to the Belfast stage they were retweeting pictures of fans waiting outside the arena and had tweeted asking fans to "get weird".
The band are due to perform in Belfast again on 19 April.
Now in the wake of the disappointment Jesy has been the victim of online trolls who told her to "kill herself" and made offensive comments about her weight.
The star had broken down onstage in Dublin on Wednesday and her fellow band members rushed to console her as she said she was feeling very emotional.
The comments were made on the singer's Instagram page with one persistent user sparking horror among Little Mix fans with her remarks.
Myself and @CGormley92 travel whole way to Belfast, book hotel, to find out @LittleMix have cancelled their two shows. Devastated
Heartbroken fans have been sharing their heartache and devastation on social media, many voicing outrage at the last minute nature of the announcement.
Many had travelled a distance to get there with some coming from Galway, Wales and Liverpool.
There were also bus loads who journeyed from Londonderry.
Tara Clelland told the Belfast Telegraph: "I was taking my 10-year-old tonight, she is devasated."
Carolyn McWilliams said: "I am gutted that tonight’s concert has been cancelled as I purchased the tickets for my daughter's 10th birthday which is today.
"We didn’t have a party or anything as she was attending the concert and now we have nothing #oneunhappylittlebirthdaygirl"
Ciara McGeough said: "I was suppose to be taking my 11 year old niece. This is a complete joke how can they go from twitter asking people waiting outside the arena to 'get weird' to canceling the show because 1 of them is sick. Seriously. She got so sick in the space of an hour."