Justin Bieber

Teen heartthrob Justin Bieber was born March 1, 1994 in Stratford, Ontario. Discovered on YouTube, the then 13-year-old singer was introduced to Usher, who immediately helped him land a record deal with Island Def Jam.

The babyfaced singer's debut single, "One Time," was an international success, as was his debut album, My World. As "Bieber Fever" took the world by storm, he released its follow-up, My World 2.0, which debuted at the top of the Billboard charts. The album featured collaborations with Ludacris and Sean Kingston.

As Bieber's popularity grew, he repeatedly made headlines for his role in several crowd control issues: he canceled a performance in Long Island, New York, in Nov. 2009, disappointing 3,000 fans; he also canceled his Australian concert in April 2010 after nearly 4,000 teens stormed past the security barricades.

The young star -- who acts as a spokesman for Proactiv skin care products -- is also known for being a ladies' man. Though he's said he's not into Miley Cyrus, he regularly proclaims his love for Beyonce and has openly flirted with Rihanna and Chelsea Handler. He is currently dating Selena Gomez.