There are 11.58 million pensioners - classed as men over 65 and women over 60 - compared to 11.52 million under-16s, according to the Office for National Statistics.
According to The Independent, these figures show that Britain's population is ageing rapidly.
With life expectancy improving, the number of deaths recorded each year has dropped from 599,000 in 2001 to 571,000 last year.
Britain's population is ageing despite record numbers of immigrants arriving in the country and immigrant mothers having more children.
According to the ONS, a record number of immigrants settled in this country last year, increasing the overall population to a record 61 million, with almost a quarter of babies now born to a foreign-born mother.
The data has re-ignited the debate over whether the Government is sufficiently prepared to deal with the long-term effects of an ageing population.
Last night, charities representing the elderly said that the latest figures should serve as a warning to the Government.
"The Government must face up to the reality of an ageing population and make a firm commitment to improve health services which enable people to stay healthy and independent for longer," the paper quoted Gordon Lishman, the director-general of Age Concern, as saying.