The first celebrity whose name was linked with Justin Timberlake's was Britney Spears. They dated from 1999, when Timberlake was 19, to 2002, though they knew each other before that, in fact they were friends ever since they appeared in 'The New Mickey Mouse Club' together.
When they broke up Timberlake was said to be dating dancer Jenna Dewan Tatum, but it was never really confirmed. Later that year he had a short relationship with Alyssa Milano, the American actress and producer.
A more important relationship was with Cameron Diaz. They were together for three years from 2003 to 2006. After that there was nothing serious until he met Jessica Biel in 2007, though there were rumours about him and Scarlett Johansson before that. Timberlake and Biel are now married. Before that heir relationship was off and on for some years and his name was linked to several other women, though Olivia Wilde is the only one he was confirmed to be dating, in 2011.