Wombats' soft fur is gray or brown with white around the nose. They have a thick, heavy body; small eyes; and a wide, flattened head. Their short, powerful legs have strong claws. Wombats' teeth are rootless and grow continuously. They also have a pouch that opens to the rear (uncommon, but not unique to wombats).

Wombats are nocturnal (active at night). They construct a complex tunnel system comprised of a large number of separate burrows that join together to form a warren at the center of their home range. Although wombats are basically solitary creatures, they have highly stable social relationships with other warren residents. The close-quarter interaction is minimal: each individual has its own burrow and feeding area. Wombats are quadrupeds (move on four legs) and can run as fast as 25 mph for short distances. They have 3 gaits: a walk, a trot, and a bound. When wombats are sleeping, they tend to lay on their back with their legs splayed open. This is probably related to thermoregulation (slowing their metabolism).