Chalinolobus morio is found in a wide range of habitats from rainforests to treeless plains (Young et al. 2008). Throughout much of its range it roosts in tree hollows with colony sizes typically less than 10 individuals. However, in Western Australia and the Nullarbor Plain it roosts in caves in larger numbers. It can also form colonies in buildings with roosts of over 1,000 recorded (Young et al. 2008). Males and females are philopatric to their natal roosts, but mating occurs when there is inter-colony mixing in winter when bats disperse away from these summer maternity roosts (Thomson 2010). Females give birth to a single young or twins. Diet consists predominantly of moths (Lumsden and Bennett 1995).

This species is endemic to Australia where it is widespread, especially in the south. There are isolated populations in central and north-western Australia, although individuals are seldom encountered. Known from sea level to relatively high elevations (e.g. up to 1,860 m at Charlotte Pass in NSW; NSW Environment and Heritage 2019).

It is known to occur in a large number of protected areas.