The rail industry contributes up to £10.1 billion each year to the UK economy, according to a new report.
Economists Oxera calculated the figure as "gross value added" from the rail sector and its supply chain.
It found that 216,000 jobs are supported by the railways and £4 billion in annual tax revenue is generated.
The research was commissioned by the Rail Delivery Group (RDG), which represents train operators and Network Rail.
The report also highlighted some environmental and social benefits of rail.
It claimed that up to 7.7 million tonnes of CO2 emissions are saved annually by the use of rail rather than other forms of transport.
As many as 865 fatal or serious accidents are prevented each year through the railways, leading to savings of up to £308 million on the "economic, medical and social cost", the report concluded.
RDG chairman Martin Griffiths said: "The railway and its supply chain are vitally important to every household in the country, linking people with jobs, paying taxes which help fund public services and increasing economic output.
"While other European countries have invested heavily in their railways, none has come close to matching the success of ours because they don't benefit from the winning combination of private sector innovation and government funding."
Mr Griffiths, who is also chief executive of Stagecoach Group - one of the UK's biggest rail operators - added: "There is more to do to improve Britain's rail services, but our network has been transformed in the last 15 years and our aim is to make it even better for passengers and businesses."
A separate study published recently by the RDG showed that the annual number of rail journeys has more than doubled since privatisation - up from 801 million in 1997 to 1.65 billion in the past 12 months.
New Labour leader Jeremy Corbyn pledged on Sunday to take rail lines back into public ownership.
He plans to create a "people's railway" that would renationalise services as franchises expired.
The RDG indicated that it would oppose the move.