The bones of a 14-year-old girl discovered at Jamestown in Virginia showed clear signs that her flesh was stripped for food.
Her remains, including part of the skull and a leg bone, dated back to the deadly winter of 1609-1610, known as the "starving time," when hundreds of early colonists died.
The skeleton fragments were found in a cellar along with those of animals that had been consumed.
There are written accounts of cannibalism at Jamestown from the time but historians had previously been sceptical.
Douglas Owsley, a forensic anthropologist at the Smithsonian National Museum of Natural History in Washington, said: "Historians have questioned, well did it happen or not happen? And this is very convincing evidence that it did.
Strike marks are seen on the skull (AP)
"This does represent a clear case of dismemberment of the body and removing of tissues for consumption."
He said the "chops" made to the girl's body had been done with a hatchet or cleaver, and appeared to be the work of someone not skilled at butchering.
"The person is truly figuring it out as they go," he added.
It is believed the girl, who has been called "Jane," was probably already dead at the time as there was a cultural stigma against killing someone for food, he said.
Researchers were able to use the skull to create a three-dimensional model of what the girl’s face might have looked like. They believe she was probably a maidservant or the daughter of a colonist.
The settlers arrived during what is thought to have been the worst drought in 800 years. After the "starving time" only 60 out of hundreds remained at Jamestown.
Captain John Smith, the colony's most famous leader, had documented a case in which a man was executed for killing, salting and eating his pregnant wife.
He wrote: "One amongst the rest did kill his wife, powdered her, and had eaten part of her before it was known, for which he was executed, as he well deserved.
"Now whether she was better roasted, boiled or carbonado'd (barbecued), I know not, but of such a dish as powdered wife I never heard of."