The capital welcomed 3.3 million business visitors last year, up from 3.2 million in 2013.
The record numbers have been attributed in part to the many flagship corporate and association events that took place, including the inaugural London Technology Week, which was attended by thousands of delegates.
Other 2014 highlights include Advertising Week Europe, Soho Create and the European Society of Pathology’s congress, which enjoyed a 23% increase in attendance compared to 2013.
Overall, London recorded 17.4 million international visitors in 2014, up 3.5% from the previous record of 16.8million visits in 2013, boosting the city's economy by £11.8bn.
Mayor of London Boris Johnson said: "These terrific new figures confirm that record numbers of tourists are spending record amounts of dosh in our amazing city. Our status as the number one destination in the world is surely beyond any doubt, and with incredible attractions like the Rugby World Cup heading our way we look forward to welcoming many thousands more visitors to London."
Gordon Innes, chief executive of London & Partners, added: "London continues to attract record numbers of international visitors, injecting billions into the capital’s economy each year. London’s attractiveness as a business destination, its expertise within the technology, life sciences and financial sectors, combined with its rich heritage and world-leading cultural offer, is expected to attract many more millions from the UK and abroad, continuing the growth of international visitor numbers in 2015."
London is expecting a boost of up to 12,000 extra hotel rooms in 2015 to meet increased demand within the city.
Properties due to open this year include the InterContinental London - The O2, Hilton London Bankside, CitizenM Tower of London and The Lanesborough London.
Several new event venues are also due to open over the coming months, with Brewer Street Car Park scheduled for a September launch and Alexandra Palace’s Victorian Theatre being restored to host events of up to 1,300 people.
The uplift in the capital was reflected across Britain, which welcomed almost 34.4 million visitors last year, a 5.2% increase compared to 2013. International tourists spent £21.8bn, up 2.8% compared to the previous year.
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