It was released through Grade A Productions and Columbia Records on 9 July 2021, as the lead single (sixth overall) from Laroi's reloaded mixtape, F*ck Love 3: Over You.

Laroi and Bieber wrote the song with Haan, FnZ members Finatik & Zac, and producers Cashmere Cat, Charlie Puth, Omer Fedi, and Blake Slatkin.

Furthermore, it reached number one in 21 other countries, including their respective natives Australia and Canada, along with Germany, the Netherlands, New Zealand, Norway, South Korea, and Sweden.

[6][9][11] The upward-darting keyboard riff, made on a Roland Juno-60 synthesizer owned by Slatkin, serves as the song's spine and eventually becomes the chorus melody.

Justin Curto from Vulture compared the song's sound to Justice single "Hold On" and album tracks "Die for You" and "Somebody".

[18] The "heartbreak-fueled" lyrics to "Stay" enforce Laroi's toxic behaviour as he sets up a story about a troubled relationship where he is at fault.

[31] Alex Zidel from HotNewHipHop felt that the song is "every bit as infectious as [one] would expect" and thought of it to be "a solid pop offering for the summer".

[32] Uproxx contributing writer Carolyn Droke stated that the "buoyant track['s]" combination of "a euphoric chorus and a driving beat" will make it "the next song of the summer".

[33] Rowat commended Laroi and Bieber's partnership as "one of the year's best surprises" and said that the song "capitalizes on both singers' skills as falsettists".

[14] DeVille described the song as "maniacally catchy" and thought it musically feels like Laroi "blasting off into a new frontier of crossover success".

[55] In addition to Bieber getting his 24th top 10 hit on the chart, he became the youngest artist to have 100 entries appear on the Hot 100 at 27 years and four months old.

[55][56] On the week of 14 August 2021, the song topped the Billboard Hot 100, dethroning BTS' "Butter" and becoming Laroi's first and Bieber's eighth number-one hit on the chart.

[68] "Stay" additionally topped the charts in Austria,[69] both regions of Belgium (Flanders and Wallonia),[70][71] Bieber's native Canada,[72] the Czech Republic,[73] Denmark,[74] Finland,[75] Germany,[76] Iceland,[77] India,[78] Israel,[79] Malaysia,[80] the Netherlands,[81] Norway,[82] Singapore,[83] Slovakia,[84] South Korea,[85] and Sweden,[86] and peaked within the top 10 in France,[87] Italy,[88] the Japan Hot 100,[89] Portugal,[90] and Switzerland.

[92] The song ascended to number one on its third week with 75.1 million streams and 13,900 in sales, making it Laroi's first leader on the chart and Bieber's second after "Peaches".

[94] The song was the longest-reigning number one on the Global 200, at the time and the first to lead it for double-digits, spending a total of eleven weeks at the top of the chart.

[99] The official music video for "Stay", directed by Colin Tilley, premiered alongside the song's release at midnight on 9 July 2021.

[102] "Stay" received its first live performance on 9 July 2021, the same day as its release, where Laroi joined Bieber during his set at the Encore Theater at the Wynn in Las Vegas.

[105] The two performed it on 10 July at the grand opening of the hotel's new supper club, Delilah, towards the end of Bieber's eight-song set.

[103] On 5 September, Bieber also brought Laroi out to perform "Stay" during his set of the Made In America Festival in Philadelphia, Pennsylvania, in which he was one of the headliners of alongside American rapper Lil Baby.

[106] Laroi appeared on a dimly lit stage to perform a stripped-back version of the song during Jimmy Kimmel Live!

[107] On 24 November, Laroi closed out the 2021 ARIA Music Awards with a punk-inspired rendition of the song backed by a full band in front of a small club audience.