The earliest evidence of human association with the parish dates to the Old Stone Age or Palaeolithic era. Fourteen hand axes and two flakes dating from this remote era were found at unspecified places in the parish. The proximity to the River Great Ouse probably played a part in human activity in the area as it is hypothesized that river travel was easier and less dangerous than travel by land at that time.
No finds from the Middle or New Stone Ages (Mesolithic and Neolithic) have been found in the parish. However, aerial photography has revealed a ring ditch in the west of the parish, north-east of Tucker’s Island. Ring ditches are associated with the Bronze Age and are usually the ploughed-out remains of round barrows. A Bronze Age axe was found in Oakley and given to Peterborough Museum but this was subsequently lost.
The final stage of prehistory was the Iron Age. Pottery from early in this period, with fragments of burnt daub was found near the Lovell Almshouses. Flint tools did not die out with the introduction of metalworking, first in bronze and then iron. Flint was easy to work and, in this part of the World, easy to find. Two flint tools for scraping animal hides were found near Oakley Bridge in 1973.
There are three areas of cropmarks in Oakley, identified by aerial photography, which may delineate prehistoric features, though without excavation or thorough field walking producing appropriate finds it is impossible to be sure. A cropmark has been identified north of Westfields Farm. It is polygonal in shape and measures thirty metres across. A group of joined cropmarks lie north-west of Browns Wood. They are on a spur of higher ground overlooking the Great Ouse valley to the west. Finally, cropmarks of roughly rectangular enclosures have been identified north of Highfield Road. They are on top of a slight ridge.