No diplomatic staff were injured in the incident, which took place around 10:00am (0900 GMT) in the exclusive Holland Park area, and a suspect was arrested.
“The official vehicle of the ambassador of Ukraine to the UK was deliberately rammed as it sat parked in front of the embassy of Ukraine’s building,” a statement from the embassy said.
Police were called immediately and quickly blocked the suspect vehicle, but it hit the ambassador’s car again.
“In response, the police were forced to open fire on the perpetrator’s vehicle,” the statement said.
“The culprit was apprehended and taken to a police station. No one of the embassy staff were injured.
“The police are investigating the suspect’s identity and motive for the attack.”
There was no immediate statement from police.