Around 4.3 million people were living with a diabetes diagnosis in the UK.
Symptoms include excessive thirst, tiredness and needing to urinate more often, although many people have no symptoms.
Nikki Joule, policy manager at the charity, said: “Type 2 diabetes is a life-changing condition that often develops slowly, especially in the early stages, when it can be very difficult to spot the symptoms.”
Those most likely to develop the condition had known diabetes risk factors such as being overweight or older.
However, the ONS said there was “considerable prevalence” in people considered at low risk of pre-diabetes, including 4% of people aged 16 to 44 and 8% who were not overweight or obese.
Those from black or Asian groups also faced more than double the risk of pre-diabetes at 22% compared with 10% of people from white, mixed and other ethnic groups.
Type 2 diabetes overall was higher among black and Asian people at 5%.
