C. dubia may refer to:
Calochlaena dubia. a fern species Centaurea dubia, the Tyrol knapweed, a perennial plant species Cercomela dubia, the sombre chat, a bird species found in Ethiopia and Somalia Ceriodaphnia dubia, a species of water flea in the class Branchiopoda Clathrina dubia, a sponge species Clausilia dubia, a species of small, very elongate, left-handed air-breathing land snail species Colias dubia, the dwarf clouded yellow, a small butterfly species found in India Coursetia dubia, a legume species found only in Ecuador
See also Dubia (disambiguation)