The song was a commercial success, reaching the top twenty in Canada, the US, Germany, the United Kingdom, France, and New Zealand and also charted in several other countries.

The accompanying music video portrays Bieber at a house party and features his mentor, Usher, and hometown friend, Ryan Butler.

Bieber performed the song in a number of live appearances including The Dome, The Next Star, and Dick Clark's New Year's Rockin' Eve with Ryan Seacrest.

[4][5] Before they produced and wrote Bieber's debut they had penned several hits, including Beyoncé's "Single Ladies", Mariah Carey's "Obsessed", Fabolous's "Throw It In the Bag" and others.

[8] The song is moderately paced, and the introduction and outro are sung in a sing-and-tell format with Bieber repetitively voicing the line "Me plus you/Imma tell you one time."

The verses are sung with backing R&B infused bass beats with a light string background in the same moderate pace before the bridge prepares for the refrain through the lines "Your world is my world/My fight is your fight/My breath is your breath/And your heart.

Unlike Lamb, Menachem said the song gave Bieber's vocals plenty of room to shine as he confidently breaks into the chorus.

[27][28] The music video, directed by Vashtie Kola, was posted by Bieber on his YouTube channel on June 13, 2009, almost a month before the single was released to iTunes.

[31] In a review of the video Entertainment Weekly's Leah Greenblat said: "Bieber does seem to share many of the qualities that made his idols the pop/R&B superstars they've become, including a clear, supple voice, pinup-boy looks, and bona fide instrument skills".

After agreeing, Bieber holds a house party and tries to get close to one girl in particular, played by Kirsten Mcdow(then known as Kristen Rodeheaver according to her maiden name), but is disappointed because he thought they were bonding but at the end of the video when they are sitting together at the pool, she kisses him on the cheek, then leaves.

The song was Bieber's ending number while on his two-show stint as an opening act for Taylor Swift's Fearless Tour.

Bieber performed the song in Las Vegas for Dick Clark's New Year's Rockin' Eve with Ryan Seacrest on December 31, 2009.

[36] While promoting the album in the United Kingdom, Bieber performed an acoustic rendition of "One Time" on BBC's Blue Peter on January 12, 2010.

[37] Bieber performed the song at a concert at the Hollywood Palladium, and August Brown of the Los Angeles Times commented, "'One Time', helmed by white-hot producer Christopher 'Tricky' Stewart, is an endearing, swaggering little thing in which Bieber convincingly jumps from Usher’s rapid-fire runs to pristine pop harmonies.

[39] Bieber later on announced on December 19, 2009, that an "exclusive unplugged Christmas [sic] version" of "One Time" would be released to iTunes the following Tuesday.

Kyle Anderson of MTV explained that the song "strips away the original track's synths and technology and leaves only Bieber's able voice".

[41] Bieber performed the acoustic version of the song when he guest starred on the Nickelodeon sitcom True Jackson, VP, during a live session with MTV, and on the British children's show Blue Peter.