Marathon day 'tinged with sadness'.
Robert Berry, aged 42, was given medical attention immediately after finishing the race but was pronounced dead at hospital.
Hugh Brasher, race director of the Virgin Money London Marathon, said: "We did very unfortunately have one death of a runner, who had finished and our thoughts are very much with the friends and family of that runner. Overall it was a fantastic day, but it always is tinged with a little bit of sadness when something like that happens."
The last death was in 2012 when event hairdresser Claire Squires, 30, from North Kilworth, Leicestershire, collapsed a mile from the finish line and died later from cardiac failure.
She was raising money for the Samaritans and in the week after her death donations to her fundraising website jumped from PS500 to more than PS1 million.