View down Fifth Avenue in Midtown Manhattan
New York mayor Michael Bloomberg announced the revised figure January 25, noting that the city had achieved its goal of attracting 50 million visitors a year ahead of schedule.
Of the 50.5 million, 40.2 million were domestic American visitors and 10.3 million were from overseas, NYC & Company said.
"The holidays are peak travel period for New York City, and 2011 proved that once again with even higher visitation levels than initially anticipated," commented NYC & Company CEO George Fertitta.
"The unseasonably warm weather during the last two weeks of the year provided an additional incentive for visitors to travel to New York City."
New York's new figures cement its position as one of the world's most visited cities, although full year figures for its major rival London haven't yet been released.
Earlier this month, figures from Euromonitor suggested that both cities may have been surpassed by Asian rivals a while back, at least in terms of international visitors.
The analysis, which uses data from 2010, suggested that both Hong Kong and Singapore pulled past London in terms of visitor arrivals a year ago, with Hong Kong welcoming 19.9 million international arrivals and Singapore clocking up 18.2 million.
London was third on the list with 14.5 million international visitors in 2010 and New York was placed eighth, with 8.9 million international visitors.
SEE PHOTOS OF NEW YORK'S LANDMARK BUILDINGS