January 2011 - November 2012
Rumors that Justin Bieber and Selena Gomez were dating began in late 2010, but they heated up in January, 2011 when photos showed the two with their arms around each other while basking poolside in Mexico. They made their public debut as a couple at the Oscars after party in March 2011.
Justin and Selena broke up in early November 2012 according to various news sources. Read more about the story here