The group – who won X Factor in 2010 – hit the exclusive Whisky Mist club in London on Sunday evening (3 November) after a triumphant return to the ITV show to perform new single 'Move'.
After leaving the stage, the band tweeted: "And now it's time to partaaayyy!!!! @WhiskeyMist :D #MOVEonout #MOVEtothegroove #MOVEoutnow xxxx."
Apparently Jesy Nelson, however, fancied a quiet night as she didn't join bandmates Leigh-Anne Pinnock, Jade Thirlwall and Perrie Edwards at the club.
Leigh-Anne pulled out all the glamour stops in a floor-length black jumpsuit and scarlet red heels, while Perrie looked rather ethereal in her grey silk jumpsuit. She kept warm by wrapping a massive grey checked scarf around herself – and flashed that stunning engagement ring in the process!
Gorgeous Jade, meanwhile, chose a black velvet jumpsuit.
Little Mix looked in high spirits and it's no wonder why! Their performance of 'Move' on X Factor was applauded by fans and viewers, including several celebrity friends.
JLS' Marvin Humes (a fellow X Factor alumnus) tweeted: "@LittleMixOffic well done girls! Loved that.. Best of luck with the single!!!"
Ex-X Factor contestant Marcus Collins added: "Can't stop smiling I'm so proud of those girls!!! @LittleMixOffic #move." Last year's runner-up Jahmene Douglas said simply: "Great performance."
Little Mix even got a shout out from One Direction's Niall Horan (yet another member of the XF family!) all the way over in Japan, where 1D were wrapping up their mammoth world tour.
"Good luck @LittleMixOffic on @TheXFactor tonight ! And with your new single! Looking forward to seeing you guys again!" he tweeted.
Also performing on Sunday night's X Factor was Taylor Swift and Snow Patrol's Gary Lightbody, while Kingsland Road became the latest act to leave the competition after a sing off with early favourite Tamera Foster.
Watch Little Mix's video for 'Move' below: