About 2,600 war pensioners living in London will benefit from the scheme
UK war pensioners and their dependants are now able to travel free of charge on public transport in London.
The scheme, announced by Mayor Boris Johnson, offers free travel on services including buses, the Underground, trams and London overground services.
It benefits those aged under 60 who get a pension under the War Pensions Scheme or Armed Forces Compensation Scheme. People over 60 already get free travel.
The scheme is expected to benefit about 2,600 war pensioners living in London.
"Far too often these heroes have been forgotten on their return to our shores but here in London we are humbled by the unsung sacrifices of our veterans," said Mr Johnson.
The Veterans Concessionary Travel Scheme is expected to save pensioners on average about £200 each year on travel.
Special Oyster photo cards will be issued to those eligible for a period of four years.
Gill Grigg, Chairwoman of the War Widows' Association of Great Britain welcomed the initiative.
"This offer of free travel will mean a lot to the daily lives of hundreds of veterans, war widows and dependants across the country, particularly those under 60 who live and work in London and use the public transport network on a daily basis," she said.
Under Secretary of State for Defence, Kevan Jones said: "This country owes a great debt to our veterans and I welcome all initiatives which honour that debt."
Mr Jones said other recent initiatives aimed at veterans include free university education, better housing and improved mental health support.
He said the government's plans also include free bus travel across England for injured veterans.