The average amount owed by over 55s is £4,400, the figures suggest, while 13% of people approaching retirement age still owe more than £10,000.
Fewer than half of those aged over 55 say they have a plan in place to clear their debts before retiring.
Almost a quarter say they don’t know how they will pay off their debts and a further 7% say they expect to delay their retirement so they can afford debt repayments.
Melanie Taylor, spokeswoman for Debt Advisory Centre, said: “It’s very worrying to see such a high number of people approaching retirement with substantial debts to clear. It’s also concerning to see the lack of planning that some are doing to ensure these debts are paid.
“Most people see their incomes drop once they move from a regular wage to a pension, which usually means they have to change their lifestyle. Trying to make debt repayments with a reduced income means that some pensioners will have to sacrifice more than is comfortable in order to cover priority bills such as a housing costs, utilities and food.
“I would advise anybody reaching retirement age who has concerns about outstanding debts to seek advice on how to put together a manageable repayment plan. The last thing we want to see is people struggling to pay for essentials such as food and heating.”
