According to research by the web analytics firm, the social network was the second most visited site by UK users, the first being search engine Google.
"During September Facebook was the second most visited website in the UK after Google, but because users view a much larger number of pages per visit, Facebook is the clear leader in terms of page views," said Robin Goad, director of research.
Internet visits to Facebook in September were 82 percent up on the same period last year, and Hitwise said it is the most popular social networking site with Brits. Hitwise said Facebook accounts for almost half (49 percent) of all web visits to social networking sites.
"Although it has fallen somewhat off the media radar in favour of Twitter recently, Facebook remains far and away the most popular social networking website in the UK," added Goad.
See also: Facebook and Twitter overtake MySpace