Caladenia dilatata, commonly known as the green-comb spider-orchid and as koolin by Aboriginal people of the Coranderrk area, is species of flowering plant in the family Orchidaceae and is endemic to south-eastern Australia. It has a single leaf and a single yellowish-green flower with reddish stripes and occurs in Victoria South Australia and Tasmania. It is similar to C. necrophylla which occurs in south-east South Australia and to C. concinna from southern New South Wales.