The accompanying video sees the girls - Jesy Nelson, Leigh-Anne Pinnock, Perrie Edwards and Jade Thirlwall - show off their vocal strength and harmonies as they sit in a derelict building and reflect on their younger selves.
The positive and uplifting song is the girls' second single to be taken from their new album Salute.
The former X Factor winners look stunning in the black and white visual, which definitely shows a more grown up side to them.
Fans have also praised the new video on Twitter as "beautiful", "powerful" and "emotional". One fan said: "#LittleMeVideo is incredible!! So inspiring. I love you girls, thank you for being the greatest role models on the earth."
Meanwhile, another commented: "If you be yourself you can be a hero. This song is so inspirational. Thank you for it girls. #LittleMeVideo."
Little Mix, along with Cher Lloyd, will be supporting Demi Lovato on the North American leg of her tour next year.
'Little Me' is due for release on 23 December.
Watch Little Mix's video for 'Little Me' below: