Evidence for aboriginal whale hunting, long thought to be a practice limited to Northwest Coast tribes in northern Washington and British Columbia’s Vancouver Island, was previously reported at the Par-Tee site on the Oregon coast between about cal AD 620 and 990. An age estimate for a humpback whale phalanx with an embedded elk bone harpoon point was based on radiocarbon dates on charcoal not directly associated with the whale bone. We present high-resolution accelerator mass spectrometry (AMS) 14C dates for purified bone collagen extracted directly from the whale phalanx and embedded harpoon point. A calibrated date for the harpoon point places the whale hunting event between about cal AD 430 and 550. The apparent 14C age of the whale bone is estimated to be 220±37 14C yr older than the marine model age at that time, consistent with values from the eastern Pacific. These new dates suggest that whale hunting took place on the Oregon coast as much as 200–500 yr earlier than previously reported and more than a millennium before historic contact in the region. Our research highlights the significance of museum collections and high-resolution AMS 14C dating for addressing a variety of issues related to ancient archaeological sites and cultures.