The Euro 5.67 million funding comes from the EU's Cleaner Hydrogen in Cities (CHIC) project and will provide finance for three more buses.
TfL already has five hydrogen buses which will come into service in central London later this year.
The buses use zero-emission hydrogen hybrid fuel cell technology and emit water vapour. The buses are part of the project to help tackle London's CO2 emissions.
Chair of the London Hydrogen Partnership and deputy mayor for policing Kit Malthouse, said: "This is knockout news for the Mayor's plans to cleanse the air we breathe every day.
"Hydrogen vehicles emit only water from their exhaust pipe, unlike the fumes and pollution petrol and diesel engines spew forth."
The buses will be delivered in partnership with ISE Corporation and Wrightbus with Ballard supplying the fuel cells and Air Products the hydrogen fuel.
London is one of five European partners benefiting from the EU investment in hydrogen technology, alongside Oslo in Norway, Milan and Bolzano in Italy and Aargau/St Gallen in Switzerland.