Chlorella (Chlorella vulgaris) is a genus of single-celled green algae, belonging to the phylum Chlorophyta. It is spherical in shape, about 2 to 10 μm in diameter, and is without flagella. Chlorella contains the green photosynthetic pigments chlorophyll-a and -b in its chloroplast. Through photosynthesis it multiplies rapidly requiring only carbon dioxide, water, sunlight, and a small amount of minerals to reproduce.

The name Chlorella is taken from the Greek word chloros meaning green and the Latin diminutive suffix ella meaning "small".

Cosmetic Uses: Used to naturally color soaps and other products various shades of green.