Zuckerberg: One billion Facebook users 'incredible'
4 October 2012 Last updated at 20:20 BST
Facebook now has more than one billion people using it every month, the company has said.
The passing of the milestone was announced by founder Mark Zuckerberg on Thursday whose company was launched just eight years ago.
Speaking on NBC TV, Mr Zuckerberg said that if his company continued to "build the best products", they could dominate the social networking market for "a long time".
The site, which was launched in 2004, is now looking towards emerging markets to build its user base further.
Rory Cellan-Jones reports.