Even more women, estimated at 25%, have been attacked by a partner or husband, the Centers for Disease Control said.
The findings form part of the first set of results from a nationwide study surveying sexual violence by intimate partners against men and women.
More than 24 people a minute reported rape, violence, or stalking, it says, with 12 million offences reported.
Experts at the Centers for Disease Control (CDC) described the results of the first year of the National Intimate Partner and Sexual Violence Survey as "astounding".
Among the key figures included in the survey's findings were:
- more than one million women reported being raped in the 12 months prior to the survey
- more than six million women and men were a victim of stalking
- more than 12 million women and men reported rape, physical violence or stalking by an intimate partner over the course of a year.
"People who experience sexual violence, stalking or intimate partner violence often deal with the effects for their entire life," said Dr Linda Degutis, director of CDC's National Center for Injury Prevention and Control.
Many of those attacked experience rape or sexual assault in their early years, with almost 80% of rape victims suffering their ordeal before before the age of 25.
Some 35% of women raped before they were aged 18 were also raped as adults, Dr Degutis added.
Among the effects measured by the study, Dr Degutis said, were increased fears for safety and incidents of post-traumatic stress among victims.
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