The remains, which include a skull, were found in the Fenwick area, between Matfen and Stamfordham, in February.
The county council’s archaeological team said the bones could be linked to a medieval settlement known to have existed in the area.
Karen Derham, assistant archaeologist, called the discovery a “fascinating insight” into the area’s history.
Historical documents show a settlement has existed at West Fenwick since at least the 13th Century, which at one point included a medieval tower.
Ms Derham said: “The burials were uncovered within the settlement area to the north of the medieval tower.
“Although there is no known record of a medieval chapel in this area, the burials are on the east-west alignment used for Christian burial and they have been radio-carbon dated to between 1280 and 1400 which fits with the date of the medieval settlement.”