One in every 14 adults in England and Wales was sexually abused as a child, according to the first research of its kind.
Some 11% of women and 3% of men - an average of 7% - said they were sexually assaulted during their childhood, according to the Crime Survey for England and Wales.
The findings of the annual survey also suggested that 567,000 adult women aged between 16 and 59, and 102,000 men in the same age bracket, suffered "sexual assault by rape or penetration" as minors.
The findings came after the Office for National Statistics (ONS) introduced new questions about childhood abuse in the survey for 2016, which was released on Thursday.
John Flatley, from the ONS's crime statistics and analysis department, said: "Police forces in England and Wales have been dealing with a growing number of reports of child abuse in recent years.
"Many of these have been historical cases reported by adults many years after the event. These new ONS estimates, based on asking adults to recall abuse experienced during their childhood, provide a more comprehensive picture than has previously been available."
Apart from sexual abuse, 9% of adults who took part in the survey said they had suffered psychological abuse and 7% physical abuse. Some 8% said they had witnesses domestic violence or abuse at home.
Apart from physical abuse, women were "significantly" more likely to report that they had been an abuse victim than men, the ONS report found.
While it found that 42% of victims suffered two or more forms of abuse, more than half of sex attack victims suffered no other form of abuse.
Those blamed for psychological or physical abuse were most likely to be the person's parents.
However, rape and penetration attack survivors said that the most likely attacker was a friend or acquaintance (30%) or other family member (26%).
Three in four victims also said they did not report what happened at the time. The most common reason given was "embarrassment or humiliation, or thinking that they would not be believed", the report found.
For other types of sexual assault, victims said that the most common perpetrator was a stranger (42%).
The report also noted that older people were more likely to report being abuse victims than younger people, but added: "It is difficult to determine whether this indicates a reduction in the prevalence of child abuse in more recent years or whether it is due to survivors being more willing to disclose past abuse the further in time they are away from the experience."