Approximately 18.8m international visitors are projected to visit the capital this year, up from 17.4m in 2014, with spending set to increase by 2.3 per cent year-on-year.
It is the second year running that the capital has topped the Index to be named the most popular tourist destination in the world.
Mayor of London Boris Johnson said: “I’m delighted that London has proudly held on to this coveted title, as we celebrate another triumphant and record-breaking year for tourism in the city.
"With its unrivalled mix of history, culture, culinary gems and cutting-edge creativity, I’m confident that these accolades will keep coming as the capital continues to surprise and excite visitors from all over the world.”
Almost a million visitors to London this year are set to come from New York, with the capital also proving popular with travelers from Amsterdam, Dublin, Frankfurt and Stockholm.
Last years’ uplift in London’s visitor numbers was reflected across the UK, which welcomed nearly 34.4m visitors – up 5.2 per cent year-on-year.
A report from Olive Insight released in 2014 argued that for regional tourism to continue to grow the UK needed to better promote the country's transport system and build on London's international reputation.
London & Partners, the Mayor’s official promotions company, are hoping to further boost tourism numbers with the upcoming London’s Autumn Season – a cultural event bringing together the city’s high-profile institutions to promote the exhibitions and events taking place later this year and strengthen London’s reputation as a global cultural powerhouse.