Zoochlorella (plural zoochlorellae) is any single green algae that lives symbiotically within the body of many freshwater and some marine invertebrates and protozoans. Zoochlorellae and zooxanthellae may both be found in the Pacific coast sea anemones Anthopleura elegantissima and A. xanthogrammica.

Zoochlorellae are responsible for the greenish color of sea anemone tentacles.