The western lowland gorilla, also known by its atypically repetitious scientific name, Gorilla gorilla gorilla, is a subspecies of the western gorilla that can be found in the lowland swamps of various types of forests in a number of central African countries. More specifically, its range is restricted to Angola, Cameroon, the Central African Republic, the Republic of Congo, the Democratic Republic of Congo, Equatorial Guinea, and Gabon.

Though the western lowland gorilla is the smallest species of gorilla, their size is still impressive. Male western lowland gorillas, which are larger than their female counterparts, can weigh 300 to 600 pounds and measure up to five to six feet in height when standing erect. On average, males weigh about 370 pounds and measure about 5'4" in height when standing erect. Female western lowland gorillas measure about five feet in height when standing erect and weigh roughly half as much as their male counterparts.

The western lowland gorilla has black skin that is covered in short, coarse black hair in all places except for their hands, feet, face, and ears. The hair on males' backs takes on a gray color increasingly with age, earning older male western lowland gorillas the nickname of "silverbacks." The western lowland gorilla has a broad face, and does not have a tail. It has long arms, its arm span measuring more than its full height, facilitating its tendency to walk in a hunched quadrupedal fashion.

Western lowland gorillas tend to live in groups. All western lowland gorillas leave the groups into which they were born, though females are always members of breeding groups, while males enter a period prior to reaching sexual maturity in which they live alone or in small, non-breeding groups. Males, however, are inclined to settle in a group that contains another male member of its family. Breeding groups are led by a silverback, and each also contain three females and their offspring.

Female western lowland gorillas reach maturity at the age of eight or nine. After becoming pregnant, a female western lowland gorilla gestates for almost nine months and gives birth to one live young. The infant clings to its mother's back for the first few years of its life, and may remain dependent on her until it is five years of age. These facts explain in large part why each female western lowland gorilla does not produce many young.

The western lowland gorilla is an herbivore, feeding on wild celery, tree bark, pulp, roots, shoots, and fruit. They may, however, eat insects on occasion. To sustain themself, a western lowland gorilla must eat about 40 pounds of food each day. The western lowland gorilla has no natural predators, but faces a grave threat from human activities including, deforestation, farming, and the expansion of human settlements. The species is currently recognized as critically endangered.