The pop singer shared “Boyz”, which samples Sean Diddy Combs’s “Bad Boy 4 Life” and features rapper Nicki Minaj, after midnight on Friday 8 October.
Nelson conceptualised and co-wrote the song, and also co-directed a reimagining of the original Diddy video with Harry James.
She apparently found inspiration for the song after going through heartbreak.
“Why do I like bad boys, what is wrong with me? Why am I attracted to anyone that looks naughty?” she recalled thinking, in a press statement.
“So I messaged [production duo Loose Change] and was like ‘you’ll think I’m a nutter but I really want to write a song about why most women like bad boys and I want to use the Diddy song’ and they were like ‘let’s do it’.”
Press material for the single describes it as a “statement of intent” from Nelson as she embarks on a solo career.
“I just want to be myself and be real,” she said.
“I want my fans to hear that they’re my stories because they genuinely are. No one has come in and told me what to write about. This is the music I’ve always wanted to make.”
Nelson recently revealed she is currently not speaking with her former Little Mix bandmates, Leigh-Anne Pinnock, Jade Thirlwall and Perrie Edwards.
“It is weird because for so many years we were as close as sisters, together every hour of the day for weeks, sharing beds, laughing, crying, just 24/7 the four of us together and then nothing,” she told Glamour.
She also admitted that she has not met the newborn babies of Edwards and Pinnock: “No. I’ve sent a few texts, but that’s it. I can’t explain it, it’s like there has to be this distance.”
Little Mix are releasing a new album, Between Us, next month.