More than one in nine of that age group are working past their 65th birthday, compared with one in 20 in 2000, according to figures from the Centre for Ageing Better.
Workers aged 65 and over are mainly self-employed and doing it part-time, but there is a growing number continuing in full-time employment up to and beyond the state pension age.
There were 457,000 workers aged 65 and above in 2000, rising to 1.43 million now, the study showed.
Dr Karen Hancock, of the Centre for Ageing Better, said: “These figures show once again the growing importance of older workers to the economy in filling labour and skills shortages.
“Around half of the substantial growth in 65+ workers since 2000 is down to demographics and the growth in the older population. The raising of the state pension age has also been a factor.
“Moving the goalposts on planned retirement dates may have compelled some to continue working into their late 60s to help their financial situation. But the increase also includes a growth in older workers who feel well enough to continue working and reaping the financial and wellbeing benefits of remaining in work.”
Almost 80,000 workers in the older age group were employed on zero-hours contracts, the report said, adding: “Working past state pension age should be a choice.”
