The Older Dryas, a stadial period between the Bølling and Allerød oscillations during the Pleistocene glacial period, is a variable cold, dry Blytt-Sernander period, observed in climatological evidence in only some regions, depending on latitude (in regions where it is not observed, the Bølling-Allerød is considered a single interstadial period).

Evidence of the Older Dryas is strongest in northern Eurasia, particularly part of North Europe roughly equivalent to Pollen zone Ic.