Bluebell, common name for several plants with bell-shaped flowers of Campanulaceae and Boraginaceae families. Common bluebells, genus Campanula [Latin, "bell"], are perennial, herbaceous plants with milky juice native to north temperate and arctic regions. More than 230 species are known worldwide; 9 species are native to Canada, 5 others have been introduced as garden escapes. The best-known Canadian species, C. rotundifolia, found from the Yukon Territory to the Atlantic provinces (in PEI, it is an escape), is the "bluebell" of Scotland or "harebell" (contraction of heatherbell).

Bluebells grow in stony tundra, rocky crevices, roadsides, rich meadows and woods, from low elevations to alpine habitats. The plants flower June-August, and the petals are joined into bell shape. The nodding bells are blue or purple, sometimes white. The mature female element (pistil) resembles a bell clapper.

Insect pollination is normal but, if it does not occur, the mature pistil bends backward and self-pollinates from pollen at the base of the bell. The fruit develops pores on the side which open to release many seeds. Lungworts, sometimes also called bluebells, belong to genus Mertensia, borage family.