The final total of 457,861 applicants from Britain and overseas represents a 10.5% increase on last year's 414,168 bidding for a place in the world's most popular marathon.
More than 56% of British entries were from people who have never run a marathon, and the majority of those are women.
"One of our goals is to inspire people to take up sport and it's fantastic that more than 210,000 people from the UK have been inspired to apply to run a marathon for the first time in 2020," event director Hugh Brasher said in a statement.
"At the first London Marathon back in 1981, fewer than 300 of the 6,300 finishers were women.
"More than 179,000 women from the UK have applied to run in 2020 and, for the third successive year, there are more female than male first-time marathon runners from the UK."
The 40th London marathon will take place on April 26, 2020.
(Reporting by Hardik Vyas in Bengaluru, editing by Ed Osmond)
