Cladia is a genus of lichen-forming fungi in the family Cladoniaceae. Cladia species have a crustose or squamulose (scaly) primary thallus and a fruticose, secondary thallus, often referred to as pseudopodetium. The type species of the genus, Cladia aggregata, is widely distributed, occurring in South America, South Africa, Australasia and South-East Asia to southern Japan and India. Most of the other species are found in the Southern Hemisphere.