The 2018 Cities & Trends Report from BCD Travel also revealed Amsterdam had switched places with Vienna, jumping from third into second place, while Paris was fourth and Zurich had slipped to fifth.
Barcelona, Copenhagen, Madrid, Milan and Frankfurt completed the top ten.
“Intra-European flights account for almost half of our total bookings in EMEA,” says Stewart Harvey, President EMEA at BCD Travel.
“With London ranking at the top we will continue to keep a very close eye on developments regarding Brexit.”
Meanwhile, New York remained the top intercontinental destination for European business travellers, followed by Shanghai, Singapore, Dubai and San Francisco.
Beijing was sixth, Chicago seventh, Tokyo eighth, Boston ninth and Los Angeles tenth.
The United States, China and India were the top overseas countries for European business travellers.