The common dwarf mongoose has soft fur ranging from yellowish red to very dark brown. It has a large pointed head, small ears, a long tail, short limbs and long claws. With a body length of 18–28 cm (7.1–11.0 in) and a weight of 210–350 gr (14–23 g), it is Africa's smallest member of the order Carnivora.

The common dwarf mongoose is a diurnal animal. It is a highly social species that lives in extended family groups of two to thirty animals. There is a strict hierarchy among same-sexed animals within a group, headed by the dominant pair (normally the oldest group members). All group members cooperate in helping to rear the pups and in guarding the group from predators.