Experts used survey data from more than 6,500 youngsters to estimate there were 207,000 new child smokers between 2010 and 2011.
The data was drawn from surveys of secondary school pupils in England in years 7 to 11 (mostly children aged 11 to 15) carried out for the Health and Social Care Information Centre.
Published in the journal Thorax, the figures for new smokers were particularly high in London.
“Each day, 67 children, more than two classrooms full, start smoking in London,” said the experts, who included specialists from Cancer Research UK and Imperial College London.
An estimated 463 children start smoking every day in England, with 50 in Scotland, 30 in Wales and 19 in Northern Ireland.
Of 74,000 children in Birmingham, nine take up smoking every day.
The experts said: “Smoking is among the largest causes of preventable deaths worldwide.
“The present data should help to raise awareness of childhood smoking and to focus attention on the need to address this important child protection issue.”
People who start smoking before the age of 15 have a higher risk of lung cancer than those who start later, they said.
The team also pointed to “compelling evidence that young people are susceptible to branding and advertising and are influenced by the depiction of smoking in films”.
They said: “Legislation is needed to counter the efforts of the tobacco industry, but this requires political will by legislators at both national and local levels.”