Australopithecus is a genus of extinct hominins that lived in Africa during the Pliocene and Early Pleistocene epochs, from about 4.4 million to 1.4 million years ago. The name "Australopithecus" means "southern ape" in Latin and Ancient Greek, and it refers to the first fossils found in South Africa. Australopithecus is a member of the subtribe Australopithecina, which also includes Ardipithecus, and sometimes Paranthropus and Kenyanthropus. The various species of Australopithecus include A. garhi, A. africanus, A. sediba, A. afarensis, A. anamensis, A. bahrelghazali, and A. deyiremeda.

Australopithecus is known for its bipedal locomotion, which means that they walked on two legs. They had a combination of ape-like and human-like features, such as a small brain size, a short face with smaller front teeth, and larger back teeth than those of apes. The foot of Australopithecus was notably apelike with elongated toes and a fully divergent great toe for moving about in trees.

Australopithecus is considered to be a direct ancestor of humans and is also considered to be a direct ancestor of later species of Australopithecus and all species in the Paranthropus genus. The various species of Australopithecus lived in different habitats, from wooded environments to open savannas. Although no tools have yet been directly associated with Australopithecus afarensis, they had hands that were well suited for the controlled manipulation of objects, and they probably did use tools.