Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section Cyanococcus within the genus Vaccinium. Vaccinium also includes cranberries, bilberries, huckleberries and Madeira blueberries. Commercial blueberries, both wild (lowbush) and cultivated (highbush), are all native to North America. The highbush varieties were introduced into Europe during the 1930s.

Commercially offered blueberries are usually from species that naturally occur only in eastern and north-central North America. Other sections in the genus are native to other parts of the world, including the Pacific Northwest and southern United States, South America, Europe and Asia. Other wild shrubs in many of these regions produce similar-looking edible berries, such as huckleberries and whortleberries (North America) and bilberries (Europe). These species are sometimes called "blueberries" and are sold as blueberry jam or other products.