"One Time" is the debut song of Canadian recording artist Justin Bieber. The song was produced and written by RedZone Entertainment's Christopher "Tricky" Stewart, Terius "The-Dream" Nash, and Kuk Harrell and production duo The Movement. It is the first single released from his debut EP, My World. It was first solicited to mainstream and rhythmic radio on May 18, 2009. It was released via digital download in the United States and Canada on July 7, 2009, and was released in several other countries during autumn 2009. An acoustic version of the song, called the "My Heart Edition" was released to iTunes on December 22, 2009. The song, moderately paced with R&B, pop, and hip-hop influences, is an ode to young love.

The song received positive reviews from critics, commending its production, vocals and quality of lyrics. The song was a commercial success, reaching the top twenty in Canada, US, Germany, United Kingdom, France and New Zealand and also charted in several other countries. The single has been certified Platinum in Canada and the United States. The accompanying music video portrays Bieber at a house party, and features his mentor, Usher and hometown friend, Ryan Butler. As of January 2010, the video had been viewed over 100 million times on the internet. The video is now the fifth most viewed video in YouTube history. 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.

One Time may refer to:

Justin Drew Bieber ( /ˈbiːbər/ BEE-bər, born March 1, 1994) is a Canadian Pop/R&B singer-songwriter, musician, and actor. Bieber was discovered in 2008 by Scooter Braun, who came across Bieber's videos on YouTube and later became his manager. Braun arranged for him to meet with Usher in Atlanta, Georgia, and Bieber was soon signed to Raymond Braun Media Group (RBMG), a joint venture between Braun and Usher, and then to a recording contract with Island Records offered by L.A. Reid. Bieber's debut single, "One Time", was released in 2009 and peaked in the top twenty in Canada and charted in the top thirty in several international markets. His debut album, the seven-track EP My World, followed in November 2009, and was soon certified platinum in the United States. He became the first artist to have seven songs from a debut album chart on the Billboard Hot 100.

Britney Jean Spears (born December 2, 1981) is an American recording artist and entertainer. Born in McComb, Mississippi, and raised in Kentwood, Louisiana, Spears began performing as a child, landing acting roles in stage productions and television shows. She signed with Jive Records in 1997 and released her debut album ...Baby One More Time in 1999, which became the best-selling album by a teenage solo artist. During her first decade in the music industry, she became a prominent figure in mainstream popular music and popular culture, followed by a much-publicized personal life. Her first two albums established her as a pop icon and broke sales records, while title tracks "...Baby One More Time" and "Oops!... I Did It Again" became international number-one hits. Spears was credited with influencing the revival of teen pop during the late 1990s, and became the 'best-selling teen aged artist of all time' before she turned 20, garnering her the honorific title of "Princess of Pop".

Jordin Brianna Sparks (born December 22, 1989) is an American pop / R&B recording artist, songwriter and actress who rose to fame as the winner of the sixth season of American Idol. She hails from Glendale, Arizona. Sparks won when she was 17 years old, making her the youngest winner in Idol history and remains the last female to win American Idol. She followed her American Idol victory with the release of her self-titled debut album in 2007, which has gone platinum in the U.S. and has sold over 2 million copies worldwide. Sparks' single, "No Air" is the highest-selling single by any American Idol contestant, selling over 3 million digital copies in the U.S. and Canada. Due to the success of her debut album and its four top 20 singles, she has received numerous awards and nominations including an American Music Award in 2008 and her first Grammy nomination in 2009. In 2009, Billboard magazine's 91st-best-selling music artist of the 2000–2009 decade.