[1][2] As of December 2023, "One More Sleep" is the 4th biggest Christmas song of the 21st century in the UK, having sold over 1.46 million units.

[5] Various media outlets speculated that this was due to the weak commercial performance of her third studio album, Glassheart, which was released in November 2012.

[11] The song was released as a digital download in the United States on 5 November through RCA Records,[12] Ireland, Italy and Switzerland through Sony Music Entertainment[13][14][15] and the United Kingdom through Syco Music on 29 November,[16] and multiple other European countries on 2 December, including France and Spain.

[17][18] Lewis uploaded a Cahill remix of the song to her official SoundCloud account on 21 November 2013.

[19] "One More Sleep" was co-written by Lewis in collaboration with Richard "Biff" Stannard, Iain James, Jez Ashurst and Bradford Ellis.

Stannard and Ash Howes produced the song, while they and Lewis carried out the vocal production.

The song utilised a multitude of instrumentalists: Keys and programming were performed by Ashurst, Stannard and Howes; Celli by Nick Holland; drums by Freddy Sheed and bass by Knight Time Horns; trombone by Barnaby Dickinson and trumpet by Graeme Flowers; James Knight performed the saxophone; strings were led by Rolf Wilson, arranged and conducted by Cliff Masterson and booked by Roz Colls; Rolf Wilson, Simon Baggs, Steve Morris, Julian Leaper, Tom Piggot Smith, Richard George, Jonathan Hill, Laura Bruce White, Tim Grant, Reiad Chibah performed the violins; and violas by Greg Walmsley, Nerys Richards.

[16][21] The hook consists of a Christmas countdown, whereby Lewis sings "Cause I got five more nights of sleeping on my own/ Four more days until you’re coming home/ Three more dreams of you and mistletoe/ Two more reasons why I love you so.

"[22] Lewis "trills" the lyrics "I've got five more nights of sleeping on my own/ Four more days until you're coming home" over the Motown inspired beat of xylophone phones and jingle bells.

Waiting the return of her partner to come home on Christmas Day, Lewis adopts an "angelic tone" as she sings "Three more dreams of you and mistletoe/ Two more reasons why I love you so.

[21] Sam Lanksy of Idolator wrote that the song is "wonderfully old-fashioned", with "ooh-oohs" sung in the background and "twinkly" production.

[22] Popjustice wrote that "One More Sleep" is "so incredible" that listeners forget that it is one of "the most toxic phrases in the English language", and awarded the song nine out of a possible ten stars.

[31] Only 300 copies separated "One More Sleep" from attaining the number-two position, which was claimed by Avicii's "Hey Brother".

[32] With "One More Sleep" peaking inside the top five at number three on the UK Singles Chart, Lewis set a new record for British female solo artist with the most top five singles in the history of the chart, bringing her total to eight.

[33] As a result, Lewis overtook Olivia Newton-John's record tally of seven top five singles.

[33] Petula Clark, Shirley Bassey, Cilla Black, Billie Piper, Geri Halliwell, Louise Redknapp, Cheryl, Emeli Sandé, Jessie J and Ellie Goulding had all had achieved six top five singles as of December 2013.

[45] In December 2016, "One More Sleep" was certified silver by the British Phonographic Industry (BPI) for exceeding 200,000 shipments and streams.

[47] In the United States, the song debuted at number 16 on the Billboard Adult Contemporary chart on 9 December.

[citation needed] In the United States, Lewis appeared on NBC's The Today Show on 4 December in New York City to talk about the album.

[citation needed] Leona performed "I Wish It Could be Christmas Everyday" on The Jonathan Ross Show and "One More Sleep" at ITV's Daybreak.