Andy Byford has been appointed the new commissioner of Transport for London.
Mr Byford, 54, who was previously president and chief executive officer of New York City Transit Authority, will begin his role on 29 June.
He said he was delighted to be appointed to the role following an international recruitment process.
The mayor of London said Mr Byford's experience would help London's transport industry to recover following the impact of Covid-19.
Mr Byford, who has spent 30 years in the transport industry, including as director of operations at Southern Railway, said his new role would be a "huge challenge" but that Transport for London (TfL) had "some of the best people in the world".
Analysis by Tom Edwards, BBC London's Transport Correspondent
What a time for a transport commissioner to be taking over.
So is Andy Byford the man for a crisis? He's just left the New York Subway which he started to improve and upgrade.
He picked up the nickname "The Train Daddy" and it seems he was well respected.
Very much a transport man, Mr Byford began his career as a graduate at London Underground.
But he now faces challenges bigger than those in the Big Apple:
- The government bailout of £1.6bn for TfL which only lasts until September. What will happen then?
- Fares have evaporated and so the whole funding model at TfL will have to be reviewed.
- It seems inevitable that Crossrail will see more delays. How will mass transit deal with social distancing?
"In the wake of the Covid-19 pandemic, all transport authorities around the world will need to reimagine how their services and projects contribute to the safe and sustainable re-start of the social and economic lives of the cities they serve," Mr Byford said.
"We will meet these challenges and will together help build an even better city for everyone."
The current commissioner, Mike Brown MVO, will stay on until 10 July.
Mr Brown is to begin a role overseeing the renovation of the historic Houses of Parliament.