Record number of visits to London
London's previous best year was 2006, when 15.6 million visited the city
The British Museum was one of the most popular attractions with 6.7 million visitors
However, the average spend-per-customer was higher for visitors from United Arab Emirates and countries in Central and South America, Asia and the Middle East.
Over the last 10 years, the number of people taking holidays in the capital also rose from 4.9 million in 2003 to 8.5 million in 2013.
The ONS said the amount of money spent by tourists in London had doubled since 2003.
Last year also saw the highest number of visits to the UK since 1961. Overseas residents made 5.6% more visits to the UK in 2013 compared with 2012, reaching a record high of more than 32 million visits.
