Little Mix worked with notable names and frequent collaborators Tayla Parx, Morten Ristorp, Robin Frid, Brian Garcia, and MNEK, who co-written and co-produced the track.

An accompanying choreography-based music video was released and features individual and group shots of the members performing dance routines, filmed in an abandoned warehouse.

[8] In November 2020, during an interview for Gay Times producer MNEK revealed "Sweet Melody" was originally crafted for a Demi Lovato songwriting camp three years prior.

Thirlwall added that “Leigh-Anne and I were in LA, and did a few sessions with Tayla Parx, who played us this song, which she’d done with MNEK, who we have worked with a lot.

Jordan Robledo of Gay Times, said: "Sweet Melody is an empowering track that touches upon on the ending of relationships and the deception that follows.

[14] Elisa Bray from i-News said "the song boasts an infectious tune with feisty lyrics matching its Latin rhythm.

"[15] Will Hodgekinson of The Times said "The lyrics 'He would lie, he would cheat over syncopated beats," shows the group singing of an unnamed boy band member on the Latin-tinged track that is Sweet Melody,".

[16] Billboard, named the song as one of the best of 2020, stating "Sweet melody is a slick banger that sees the group delivering a sizzling takedown of some dude in a band who "would lie, would cheat, over syncopated beats.

[19] Attitude included the song #3 on their list of 32 greatest Little Mix singles of all time writing "Sweet Melody was an instant girl group classic.

The video features different segments with individual shots of all four members performing their own choreography with back up dancers and coming together for a group routine.

In 2021, she revealed that the shooting of the video caused her to experience panic attacks while on set, recalling that she was also rushed to the hospital following symptoms stemming from an eating disorder she was dealing with at the time.

The incident was particularly worsened by the label's demands during the COVID-19 pandemic, after which her mother and the remaining three members advised that she should leave Little Mix to focus on her mental health.