Mandarin has jumped from the 8th to the 4th most commonly quoted language on job applications, while Cantonese is now the 6th most commonly cited language among City workers, said recruitment firm Astbury Marsden.
The increase was said to be the result of investment banks employing more Chinese speakers to deal with a recent surge in work with Asian markets, as well as more investment from China into the capital.
Jonathan Nicholson, managing director of Astbury Marsden, said: "Chancellor George Osborne has made great strides recently to get agreement with the Chinese government for London to be the location for the first Western-based RMB clearing bank.
"Our research on languages spoken in the City shows that London is well equipped to achieve this as it is already home to a burgeoning business in renminbi financial services and products such as trade finance and foreign exchange. This trend is likely to continue."