Uber will not be issued a new private hire licence, Transport for London (TfL) has said.
TfL has concluded the ride-hailing app firm was not fit and proper to hold a private hire operator licence.
Uber's conduct demonstrated a lack of corporate responsibility which could have potential public safety and security implications, it said.
Uber said the decision would "show the world that, far from being open, London is closed to innovative companies".
Uber has 21 days to appeal, during which it can continue to operate.
Mayor of London Sadiq Khan said in a statement: "I fully support TfL's decision - it would be wrong if TfL continued to license Uber if there is any way that this could pose a threat to Londoners' safety and security."
General secretary of the Licensed Taxi Drivers' Association Steve McNamara: "The mayor has made the right call not to relicense Uber."
"We expect Uber will again embark on a spurious legal challenge against the mayor and TfL, and we will urge the court to uphold this decision. This immoral company has no place on London's streets".