The southern forest bat (Vespadelus regulus) is a species of vesper bat in the family Vespertilionidae. It is found only in Australia. It is endemic to the southern parts of Australia and is found roosting in tree hollows and sometimes in buildings. It is found in wet to dry sclerophyll forests and low shrub woodlands. They display a strong preference for roosting in large, mature trees in the mid-decay stages, which correspond to trees with large numbers of suitable hollows. It has a reddish-brown uppermost colouration whilst its underbody is a grey colour. It has a very short snout, large ears, a flat skull and a triangle shaped head.